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Sample records for acetylation

  1. Acetylation dynamics and stoichiometry in Saccharomyces cerevisiae

    Weinert, Brian Tate; Iesmantavicius, Vytautas; Moustafa, Tarek; Schölz, Christian; Wagner, Sebastian A; Magnes, Christoph; Zechner, Rudolf; Choudhary, Chuna Ram

    2014-01-01

    Lysine acetylation is a frequently occurring posttranslational modification; however, little is known about the origin and regulation of most sites. Here we used quantitative mass spectrometry to analyze acetylation dynamics and stoichiometry in Saccharomyces cerevisiae. We found that acetylation...

  2. Acetyltransferase and human hemoglobin acetylation

    A minor component of human fetal hemoglobin (Hb F) is acetylated at the amino-terminus of the γ-globin chains. A similar minor component of Hb F is formed during translation of cord blood mRNA in the rabbit reticulocyte lysate system. The acetylation appeared to be enzymatic. This system contains an acetyltransferase capable of acetylating histones and hemoglobins. The enzyme, partially purified by histone-Sepharose affinity chromatography was capable of incorporating labeled acetyl- group from 1-[14C-acetyl]-CoA into both human Hb F0 and HB A0, but at a lower rate than for histones. Characterization of the labeled products indicated that the α-chains of both hemoglobins were being acetylated presumably at a lysyl-residue, but in the case of Hb F0 the amino-terminus of the γ-globin chains was acetylated as well. While histone-Sepharose bound more than 95% of the enzyme, Sepharose linked Hb F0, γ-globin chains, and Hb Bart's bound 14, 5, and 12% of the activity, respectively. Enzyme bound to these resins was not any more active on the hemoglobins than was the enzyme bound to the histone-Sepharose. The histone-Sepharose was also used to detect the enzyme in human cord blood red cells separated by dextran 40 density gradient centrifugation. Activity was found mostly in the young cells, and was directly related to the number of reticulocytes present in any one fraction

  3. Regulation of intermediary metabolism by protein acetylation

    Guan, Kun-Liang; Xiong, Yue

    2010-01-01

    Extensive studies during the past four decades have identified important roles for lysine acetylation in the regulation of nuclear transcription. Recent proteomic analyses on protein acetylation uncovered a large number of acetylated proteins in the cytoplasm and mitochondria, including most enzymes involved in intermediate metabolism. Acetylation regulates metabolic enzymes by multiple mechanisms, including via enzymatic activation or inhibition, and by influencing protein stability. Convers...

  4. Fatal Intoxication with Acetyl Fentanyl.

    Cunningham, Susan M; Haikal, Nabila A; Kraner, James C

    2016-01-01

    Among the new psychoactive substances encountered in forensic investigations is the opioid, acetyl fentanyl. The death of a 28-year-old man from recreational use of this compound is reported. The decedent was found in the bathroom of his residence with a tourniquet secured around his arm and a syringe nearby. Postmortem examination findings included marked pulmonary and cerebral edema and needle track marks. Toxicological analysis revealed acetyl fentanyl in subclavian blood, liver, vitreous fluid, and urine at concentrations of 235 ng/mL, 2400 ng/g, 131 ng/mL, and 234 ng/mL, respectively. Acetyl fentanyl was also detected in the accompanying syringe. Death was attributed to recreational acetyl fentanyl abuse, likely through intravenous administration. The blood acetyl fentanyl concentration is considerably higher than typically found in fatal fentanyl intoxications. Analysis of this case underscores the need for consideration of a wide range of compounds with potential opioid-agonist activity when investigating apparent recreational drug-related deaths. PMID:26389815

  5. Protein Acetylation in Archaea, Bacteria, and Eukaryotes

    Jörg Soppa

    2010-01-01

    Full Text Available Proteins can be acetylated at the alpha-amino group of the N-terminal amino acid (methionine or the penultimate amino acid after methionine removal or at the epsilon-amino group of internal lysines. In eukaryotes the majority of proteins are N-terminally acetylated, while this is extremely rare in bacteria. A variety of studies about N-terminal acetylation in archaea have been reported recently, and it was revealed that a considerable fraction of proteins is N-terminally acetylated in haloarchaea and Sulfolobus, while this does not seem to apply for methanogenic archaea. Many eukaryotic proteins are modified by differential internal acetylation, which is important for a variety of processes. Until very recently, only two bacterial proteins were known to be acetylation targets, but now 125 acetylation sites are known for E. coli. Knowledge about internal acetylation in archaea is extremely limited; only two target proteins are known, only one of which—Alba—was used to study differential acetylation. However, indications accumulate that the degree of internal acetylation of archaeal proteins might be underestimated, and differential acetylation has been shown to be essential for the viability of haloarchaea. Focused proteomic approaches are needed to get an overview of the extent of internal protein acetylation in archaea.

  6. Acetyl-Phosphate Is a Critical Determinant of Lysine Acetylation in E. coli

    Weinert, Brian T; Iesmantavicius, Vytautas; Wagner, Sebastian A;

    2013-01-01

    Lysine acetylation is a frequently occurring posttranslational modification in bacteria; however, little is known about its origin and regulation. Using the model bacterium Escherichia coli (E. coli), we found that most acetylation occurred at a low level and accumulated in growth-arrested cells in...... acetylate lysine residues in vitro and that AcP levels are correlated with acetylation levels in vivo, suggesting that AcP may acetylate proteins nonenzymatically in cells. These results uncover a critical role for AcP in bacterial acetylation and indicate that most acetylation in E. coli occurs at a low...

  7. Swelling of acetylated wood in organic liquids

    Obataya, E; Obataya, Eiichi; Gril, Joseph

    2005-01-01

    To investigate the affinity of acetylated wood for organic liquids, Yezo spruce wood specimens were acetylated with acetic anhydride, and their swelling in various liquids were compared to those of untreated specimens. The acetylated wood was rapidly and remarkably swollen in aprotic organic liquids such as benzene and toluene in which the untreated wood was swollen only slightly and/or very slowly. On the other hand, the swelling of wood in water, ethylene glycol and alcohols remained unchanged or decreased by the acetylation. Consequently the maximum volume of wood swollen in organic liquids was always larger than that in water. The effect of acetylation on the maximum swollen volume of wood was greater in liquids having smaller solubility parameters. The easier penetration of aprotic organic liquids into the acetylated wood was considered to be due to the scission of hydrogen bonds among the amorphous wood constituents by the substitution of hydroxyl groups with hydrophobic acetyl groups.

  8. Histone Acetylation in Drug Addiction

    Renthal, William; Nestler, Eric J.

    2009-01-01

    Regulation of chromatin structure through post-translational modifications of histones (e.g. acetylation) has emerged as an important mechanism to translate a variety of environmental stimuli, including drugs of abuse, into specific changes in gene expression. Since alterations in gene expression are thought to contribute to the development and maintenance of the addicted state, recent efforts are aimed at identifying how drugs of abuse alter chromatin structure and the enzymes which regulate...

  9. Analysis of acetylation stoichiometry suggests that SIRT3 repairs nonenzymatic acetylation lesions.

    Weinert, Brian T; Moustafa, Tarek; Iesmantavicius, Vytautas; Zechner, Rudolf; Choudhary, Chunaram

    2015-11-01

    Acetylation is frequently detected on mitochondrial enzymes, and the sirtuin deacetylase SIRT3 is thought to regulate metabolism by deacetylating mitochondrial proteins. However, the stoichiometry of acetylation has not been studied and is important for understanding whether SIRT3 regulates or suppresses acetylation. Using quantitative mass spectrometry, we measured acetylation stoichiometry in mouse liver tissue and found that SIRT3 suppressed acetylation to a very low stoichiometry at its target sites. By examining acetylation changes in the liver, heart, brain, and brown adipose tissue of fasted mice, we found that SIRT3-targeted sites were mostly unaffected by fasting, a dietary manipulation that is thought to regulate metabolism through SIRT3-dependent deacetylation. Globally increased mitochondrial acetylation in fasted liver tissue, higher stoichiometry at mitochondrial acetylation sites, and greater sensitivity of SIRT3-targeted sites to chemical acetylation in vitro and fasting-induced acetylation in vivo, suggest a nonenzymatic mechanism of acetylation. Our data indicate that most mitochondrial acetylation occurs as a low-level nonenzymatic protein lesion and that SIRT3 functions as a protein repair factor that removes acetylation lesions from lysine residues. PMID:26358839

  10. A Method to determine lysine acetylation stoichiometries

    Nakayasu, Ernesto S.; Wu, Si; Sydor, Michael A.; Shukla, Anil K.; Weitz, Karl K.; Moore, Ronald J.; Hixson, Kim K.; Kim, Jong Seo; Petyuk, Vladislav A.; Monroe, Matthew E.; Pasa-Tolic, Ljiljana; Qian, Weijun; Smith, Richard D.; Adkins, Joshua N.; Ansong, Charles

    2014-07-21

    A major bottleneck to fully understanding the functional aspects of lysine acetylation is the lack of stoichiometry information. Here we describe a mass spectrometry method using a combination of isotope labeling and detection of a diagnostic fragment ion to determine the stoichiometry of lysine acetylation on proteins globally. Using this technique, we determined the modification occupancy on hundreds of acetylated peptides from cell lysates and cross-validated the measurements via immunoblotting.

  11. Analysis of acetylation stoichiometry suggests that SIRT3 repairs nonenzymatic acetylation lesions

    Weinert, Brian T; Moustafa, Tarek; Iesmantavicius, Vytautas;

    2015-01-01

    Acetylation is frequently detected on mitochondrial enzymes, and the sirtuin deacetylase SIRT3 is thought to regulate metabolism by deacetylating mitochondrial proteins. However, the stoichiometry of acetylation has not been studied and is important for understanding whether SIRT3 regulates or...... suppresses acetylation. Using quantitative mass spectrometry, we measured acetylation stoichiometry in mouse liver tissue and found that SIRT3 suppressed acetylation to a very low stoichiometry at its target sites. By examining acetylation changes in the liver, heart, brain, and brown adipose tissue of...... fasted mice, we found that SIRT3-targeted sites were mostly unaffected by fasting, a dietary manipulation that is thought to regulate metabolism through SIRT3-dependent deacetylation. Globally increased mitochondrial acetylation in fasted liver tissue, higher stoichiometry at mitochondrial acetylation...

  12. Acetylation of woody lignocellulose: significance and regulation

    Prashant Mohan-Anupama Pawar

    2013-05-01

    Full Text Available Non-cellulosic cell wall polysaccharides constitute approximately one quarter of usable biomass for human exploitation. In contrast to cellulose, these components are usually substituted by O-acetyl groups, which affect their properties and interactions with other polymers, thus affecting their solubility and extractability. However, details of these interactions are still largely obscure. Moreover, polysaccharide hydrolysis to constituent monosaccharides, is hampered by the presence of O-acetyl groups, necessitating either enzymatic (esterase or chemical de-acetylation, increasing the costs and chemical consumption. Reduction of polysaccharide acetyl content in planta is a way to modify lignocellulose towards improved saccharification. In this review we: 1 summarize literature on lignocellulose acetylation in different tree species, 2 present data and current hypotheses concerning the role of O-acetylation in determining woody lignocellulose properties, 3 describe plant proteins involved in lignocellulose O-acetylation, 4 give examples of microbial enzymes capable to de-acetylate lignocellulose, and 5 discuss prospects for exploiting these enzymes in planta to modify xylan acetylation.

  13. Acetylation-Mediated Suppression of Transcription-Independent Memory: Bidirectional Modulation of Memory by Acetylation

    Katja Merschbaecher; Jakob Haettig; Uli Mueller

    2012-01-01

    Learning induced changes in protein acetylation, mediated by histone acetyl transferases (HATs), and the antagonistic histone deacetylases (HDACs) play a critical role in memory formation. The status of histone acetylation affects the interaction between the transcription-complex and DNA and thus regulates transcription-dependent processes required for long-term memory (LTM). While the majority of studies report on the role of elevated acetylation in memory facilitation, we address the impact...

  14. UNIQUE ACETYLATION OF OLIGOSACCHARIDES BY TRICHODERMA REESEI ACETYL ESTERASE IN WATER - VINYL ACETATE MIXTURE

    Purified T. reesei RUT C-30 acetyl esterase catalyzes acetyl transfer to a variety of carbohydrates in water in the presence of vinyl acetate as the acetyl group donor. The degree of conversion and the number of formed acetates depended on the acceptor used. With some acceptors, such as methyl or ...

  15. Acetyl coenzyme A: alpha-glucosaminide N-acetyltransferase. Evidence for a transmembrane acetylation mechanism

    The lysosomal membrane enzyme acetyl-CoA: alpha-glucosaminide N-acetyltransferase catalyzes the transfer of an acetyl group from acetyl-CoA to terminal alpha-linked glucosamine residues of heparan sulfate. The reaction mechanism was examined using highly purified lysosomal membranes from rat liver. The reaction was followed by measuring the acetylation of a monosaccharide acetyl acceptor, glucosamine. The enzyme reaction was optimal above pH 5.5, and a 2-3-fold stimulation of activity was observed when the membranes were assayed in the presence of 0.1% taurodeoxycholate. Double reciprocal analysis and product inhibition studies indicated that the enzyme works by a Di-Iso Ping Pong Bi Bi mechanism. Further evidence to support this mechanism was provided by characterization of the enzyme half-reactions. Membranes incubated with acetyl-CoA and [3H]CoA were found to produce acetyl-[3H]CoA. This exchange was optimal at pH values above 7.0. Treating membranes with [3H] acetyl-CoA resulted in the formation of an acetyl-enzyme intermediate. The acetyl group could then be transferred to glucosamine, forming [3H]N-acetylglucosamine. The transfer of the acetyl group from the enzyme to glucosamine was optimal between pH 4 and 5. The results suggest that acetyl-CoA does not cross the lysosomal membrane. Instead, the enzyme is acetylated on the cytoplasmic side of the lysosome and the acetyl group is then transferred to the inside where it is used to acetylate heparan sulfate

  16. Proteomic profiling of lysine acetylation in Pseudomonas aeruginosa reveals the diversity of acetylated proteins.

    Ouidir, Tassadit; Cosette, Pascal; Jouenne, Thierry; Hardouin, Julie

    2015-07-01

    Protein lysine acetylation is a reversible and highly regulated post-translational modification with the well demonstrated physiological relevance in eukaryotes. Recently, its important role in the regulation of metabolic processes in bacteria was highlighted. Here, we reported the lysine acetylproteome of Pseudomonas aeruginosa using a proteomic approach. We identified 430 unique peptides corresponding to 320 acetylated proteins. In addition to the proteins involved in various metabolic pathways, several enzymes contributing to the lipopolysaccharides biosynthesis were characterized as acetylated. This data set illustrated the abundance and the diversity of acetylated lysine proteins in P. aeruginosa and opens opportunities to explore the role of the acetylation in the bacterial physiology. PMID:25900529

  17. Investigation of acetyl migrations in furanosides

    Migaud ME

    2006-07-01

    Full Text Available Abstract Standard reaction conditions for the desilylation of acetylated furanoside (riboside, arabinoside and xyloside derivatives facilitate acyl migration. Conditions which favour intramolecular and intermolecular mechanisms have been identified with intermolecular transesterifications taking place under mild basic conditions when intramolecular orthoester formations are disfavoured. In acetyl ribosides, acyl migration could be prevented when desilylation was catalysed by cerium ammonium nitrate.

  18. Histone Acetylation in Fungal Pathogens of Plants

    Junhyun Jeon

    2014-03-01

    Full Text Available Acetylation of histone lysine residues occurs in different organisms ranging from yeast to plants and mammals for the regulation of diverse cellular processes. With the identification of enzymes that create or reverse this modification, our understanding on histone acetylation has expanded at an amazing pace during the last two decades. In fungal pathogens of plants, however, the importance of such modification has only just begun to be appreciated in the recent years and there is a dearth of information on how histone acetylation is implicated in fungal pathogenesis. This review covers the current status of research related to histone acetylation in plant pathogenic fungi and considers relevant findings in the interaction between fungal pathogens and host plants. We first describe the families of histone acetyltransferases and deacetylases. Then we provide the cases where histone acetylation was investigated in the context of fungal pathogenesis. Finally, future directions and perspectives in epigenetics of fungal pathogenesis are discussed.

  19. Acetylation-mediated suppression of transcription-independent memory: bidirectional modulation of memory by acetylation.

    Katja Merschbaecher

    Full Text Available Learning induced changes in protein acetylation, mediated by histone acetyl transferases (HATs, and the antagonistic histone deacetylases (HDACs play a critical role in memory formation. The status of histone acetylation affects the interaction between the transcription-complex and DNA and thus regulates transcription-dependent processes required for long-term memory (LTM. While the majority of studies report on the role of elevated acetylation in memory facilitation, we address the impact of both, increased and decreased acetylation on formation of appetitive olfactory memory in honeybees. We show that learning-induced changes in the acetylation of histone H3 at aminoacid-positions H3K9 and H3K18 exhibit distinct and different dynamics depending on the training strength. A strong training that induces LTM leads to an immediate increase in acetylation at H3K18 that stays elevated for hours. A weak training, not sufficient to trigger LTM, causes an initial increase in acetylation at H3K18, followed by a strong reduction in acetylation at H3K18 below the control group level. Acetylation at position H3K9 is not affected by associative conditioning, indicating specific learning-induced actions on the acetylation machinery. Elevating acetylation levels by blocking HDACs after conditioning leads to an improved memory. While memory after strong training is enhanced for at least 2 days, the enhancement after weak training is restricted to 1 day. Reducing acetylation levels by blocking HAT activity after strong training leads to a suppression of transcription-dependent LTM. The memory suppression is also observed in case of weak training, which does not require transcription processes. Thus, our findings demonstrate that acetylation-mediated processes act as bidirectional regulators of memory formation that facilitate or suppress memory independent of its transcription-requirement.

  20. Efficient acetylation of primary amines and amino acids in environmentally benign brine solution using acetyl chloride

    Kaushik Basu; Suchandra Chakraborty; Achintya Kumar Sarkar; Chandan Saha

    2013-05-01

    Acetyl chloride is one of the most commonly available and cheap acylating agent but its high reactivity and concomitant instability in water precludes its use to carry out acetylation in aqueous medium. The present methodology illustrates the efficient acetylation of primary amines and amino acids in brine solution by means of acetyl chloride under weakly basic condition in the presence of sodium acetate and/or triethyl amine followed by trituration with aqueous saturated bicarbonate solution. This effort represents the first efficient use of this most reactive but cheap acetylating agent to acetylate amines in excellent yields in aqueous medium. This is a potentially useful green chemical transformation where reaction takes place in environment-friendly brine solution leading to easy work-up and isolation of the amide derivatives. Mechanistic rationale of this methodology is also important.

  1. Levels of histone acetylation in thyroid tumors.

    Puppin, Cinzia; Passon, Nadia; Lavarone, Elisa; Di Loreto, Carla; Frasca, Francesco; Vella, Veronica; Vigneri, Riccardo; Damante, Giuseppe

    2011-08-12

    Histone acetylation is a major mechanism to regulate gene transcription. This post-translational modification is modified in cancer cells. In various tumor types the levels of acetylation at several histone residues are associated to clinical aggressiveness. By using immunohistochemistry we show that acetylated levels of lysines at positions 9-14 of H3 histone (H3K9-K14ac) are significantly higher in follicular adenomas (FA), papillary thyroid carcinomas (PTC), follicular thyroid carcinomas (FTC) and undifferentiated carcinomas (UC) than in normal tissues (NT). Similar data have been obtained when acetylated levels of lysine 18 of H3 histone (H3K18ac) were evaluated. In this case, however, no difference was observed between NT and UC. When acetylated levels of lysine 12 of H4 histone (H4K12ac) were evaluated, only FA showed significantly higher levels in comparison with NT. These data indicate that modification histone acetylation is an early event along thyroid tumor progression and that H3K18 acetylation is switched off in the transition between differentiated and undifferentiated thyroid tumors. By using rat thyroid cell lines that are stably transfected with doxycyclin-inducible oncogenes, we show that the oncoproteins RET-PTC, RAS and BRAF increase levels of H3K9-K14ac and H3K18ac. In the non-tumorigenic rat thyroid cell line FRTL-5, TSH increases levels of H3K18ac. However, this hormone decreases levels of H3K9-K14ac and H4K12ac. In conclusion, our data indicate that neoplastic transformation and hormonal stimulation can modify levels of histone acetylation in thyroid cells. PMID:21763277

  2. p53 Acetylation: Regulation and Consequences

    Reed, Sara M. [Department of Pharmacology, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States); Medical Scientist Training Program, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States); Quelle, Dawn E., E-mail: dawn-quelle@uiowa.edu [Department of Pharmacology, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States); Medical Scientist Training Program, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States); Department of Pathology, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States)

    2014-12-23

    Post-translational modifications of p53 are critical in modulating its tumor suppressive functions. Ubiquitylation, for example, plays a major role in dictating p53 stability, subcellular localization and transcriptional vs. non-transcriptional activities. Less is known about p53 acetylation. It has been shown to govern p53 transcriptional activity, selection of growth inhibitory vs. apoptotic gene targets, and biological outcomes in response to diverse cellular insults. Yet recent in vivo evidence from mouse models questions the importance of p53 acetylation (at least at certain sites) as well as canonical p53 functions (cell cycle arrest, senescence and apoptosis) to tumor suppression. This review discusses the cumulative findings regarding p53 acetylation, with a focus on the acetyltransferases that modify p53 and the mechanisms regulating their activity. We also evaluate what is known regarding the influence of other post-translational modifications of p53 on its acetylation, and conclude with the current outlook on how p53 acetylation affects tumor suppression. Due to redundancies in p53 control and growing understanding that individual modifications largely fine-tune p53 activity rather than switch it on or off, many questions still remain about the physiological importance of p53 acetylation to its role in preventing cancer.

  3. p53 Acetylation: Regulation and Consequences

    Post-translational modifications of p53 are critical in modulating its tumor suppressive functions. Ubiquitylation, for example, plays a major role in dictating p53 stability, subcellular localization and transcriptional vs. non-transcriptional activities. Less is known about p53 acetylation. It has been shown to govern p53 transcriptional activity, selection of growth inhibitory vs. apoptotic gene targets, and biological outcomes in response to diverse cellular insults. Yet recent in vivo evidence from mouse models questions the importance of p53 acetylation (at least at certain sites) as well as canonical p53 functions (cell cycle arrest, senescence and apoptosis) to tumor suppression. This review discusses the cumulative findings regarding p53 acetylation, with a focus on the acetyltransferases that modify p53 and the mechanisms regulating their activity. We also evaluate what is known regarding the influence of other post-translational modifications of p53 on its acetylation, and conclude with the current outlook on how p53 acetylation affects tumor suppression. Due to redundancies in p53 control and growing understanding that individual modifications largely fine-tune p53 activity rather than switch it on or off, many questions still remain about the physiological importance of p53 acetylation to its role in preventing cancer

  4. p53 Acetylation: Regulation and Consequences

    Sara M. Reed

    2014-12-01

    Full Text Available Post-translational modifications of p53 are critical in modulating its tumor suppressive functions. Ubiquitylation, for example, plays a major role in dictating p53 stability, subcellular localization and transcriptional vs. non-transcriptional activities. Less is known about p53 acetylation. It has been shown to govern p53 transcriptional activity, selection of growth inhibitory vs. apoptotic gene targets, and biological outcomes in response to diverse cellular insults. Yet recent in vivo evidence from mouse models questions the importance of p53 acetylation (at least at certain sites as well as canonical p53 functions (cell cycle arrest, senescence and apoptosis to tumor suppression. This review discusses the cumulative findings regarding p53 acetylation, with a focus on the acetyltransferases that modify p53 and the mechanisms regulating their activity. We also evaluate what is known regarding the influence of other post-translational modifications of p53 on its acetylation, and conclude with the current outlook on how p53 acetylation affects tumor suppression. Due to redundancies in p53 control and growing understanding that individual modifications largely fine-tune p53 activity rather than switch it on or off, many questions still remain about the physiological importance of p53 acetylation to its role in preventing cancer.

  5. Intracellular Acetyl Unit Transport in Fungal Carbon Metabolism

    Strijbis, K.; Distel, B.

    2010-01-01

    Acetyl coenzyme A (acetyl-CoA) is a central metabolite in carbon and energy metabolism. Because of its amphiphilic nature and bulkiness, acetyl-CoA cannot readily traverse biological membranes. In fungi, two systems for acetyl unit transport have been identified: a shuttle dependent on the carrier carnitine and a (peroxisomal) citrate synthase-dependent pathway. In the carnitine-dependent pathway, carnitine acetyltransferases exchange the CoA group of acetyl-CoA for carnitine, thereby forming...

  6. Reversible lysine acetylation controls the activity of the mitochondrial enzyme acetyl-CoA synthetase 2

    Schwer, Bjoern; Bunkenborg, Jakob; Verdin, Regis O; Andersen, Jens S; Verdin, Eric

    2006-01-01

    We report that human acetyl-CoA synthetase 2 (AceCS2) is a mitochondrial matrix protein. AceCS2 is reversibly acetylated at Lys-642 in the active site of the enzyme. The mitochondrial sirtuin SIRT3 interacts with AceCS2 and deacetylates Lys-642 both in vitro and in vivo. Deacetylation of AceCS2 b...

  7. Oxidative Debenzylation and Acetylation of Hexabenzylhexaazaisowutzitane

    2002-01-01

    The oxidative reactivity of hexabenzylhexaazaisowutzitane(HBIW)under different conditions was studied. It was found that the N-benzyl groups were found to form benzoyl group after oxidation. They might also be first debenzylated and then acetylated by potassium permanganate in acetic anhydride/DMF.

  8. Property enhancement of optically transparent bionanofiber composites by acetylation

    Nogi, Masaya; Abe, Kentaro; Handa, Keishin; Nakatsubo, Fumiaki; Ifuku, Shinsuke; Yano, Hiroyuki

    2006-12-01

    The authors studied acetylation of bacterial cellulose (BC) nanofibers to widen the applications of BC nanocomposites in optoelectronic devices. The slight acetylation of BC nanofibers significantly reduces the hygroscopicity of BC nanocomposites, while maintaining their high optical transparency and thermal stability. Furthermore, the degradation in optical transparency at elevated temperature (200°C) was significantly reduced by acetylation treatment. Therefore, the acetylation of bionanofibers has an extraordinary potential as treatment for property enhancement of bionanofiber composites.

  9. Phosphorylation and Acetylation of Acyl-CoA Synthetase- I

    Frahm, Jennifer L; Li, Lei O; Grevengoed, Trisha J;

    2011-01-01

    acetylated amino acids by mass spectrometry. We then compared these results to the post-translational modifications observed in vivo in liver and brown adipose tissue after mice were fasted or exposed to a cold environment. We identified universal N-terminal acetylation, 15 acetylated lysines, and 25...

  10. Dynamic Protein Acetylation in Plant–Pathogen Interactions

    Song, Gaoyuan; Walley, Justin W.

    2016-01-01

    Pathogen infection triggers complex molecular perturbations within host cells that results in either resistance or susceptibility. Protein acetylation is an emerging biochemical modification that appears to play central roles during host–pathogen interactions. To date, research in this area has focused on two main themes linking protein acetylation to plant immune signaling. Firstly, it has been established that proper gene expression during defense responses requires modulation of histone acetylation within target gene promoter regions. Second, some pathogens can deliver effector molecules that encode acetyltransferases directly within the host cell to modify acetylation of specific host proteins. Collectively these findings suggest that the acetylation level for a range of host proteins may be modulated to alter the outcome of pathogen infection. This review will focus on summarizing our current understanding of the roles of protein acetylation in plant defense and highlight the utility of proteomics approaches to uncover the complete repertoire of acetylation changes triggered by pathogen infection. PMID:27066055

  11. Acetylation Is Indispensable for p53 Activation

    Tang, Yi; Zhao, Wenhui; Chen, Yue; Zhao, Yingming; Gu, Wei

    2008-01-01

    The activation of the tumor suppressor p53 facilitates the cellular response to genotoxic stress; however, the p53 response can only be executed if its interaction with its inhibitor Mdm2 is abolished. There have been conflicting reports on the question of whether p53 posttranslational modifications, such as phosphorylation or acetylation, are essential or only play a subtle, fine-tuning role in the p53 response. Thus, it remains unclear whether p53 modification is absolutely required for its...

  12. p53 Acetylation: Regulation and Consequences

    Reed, Sara M.; Quelle, Dawn E.

    2014-01-01

    Post-translational modifications of p53 are critical in modulating its tumor suppressive functions. Ubiquitylation, for example, plays a major role in dictating p53 stability, subcellular localization and transcriptional vs. non-transcriptional activities. Less is known about p53 acetylation. It has been shown to govern p53 transcriptional activity, selection of growth inhibitory vs. apoptotic gene targets, and biological outcomes in response to diverse cellular insults. Yet recent in vivo ev...

  13. The neurobiology of acetyl-L-carnitine.

    Traina, Giovanna

    2016-01-01

    A large body of evidence points to the positive effects of dietary supplementation of acetyl-L-carnitine (ALC). Its use has shown health benefits in neuroinflammation, which is a common denominator in a host of neurodegenerative diseases. ALC is the principal acetyl ester of L-Carnitine (LC), and it plays an essential role in intermediary metabolism, acting as a donor of acetyl groups and facilitating the transfer of fatty acids from cytosol to mitochondria during beta-oxidation. Dietary supplementation of ALC exerts neuroprotective, neurotrophic, antidepressive and analgesic effects in painful neuropathies. ALC also has antioxidant and anti-apoptotic activity. Moreover, ALC exhibits positive effects on mitochondrial metabolism, and shows promise in the treatment of aging and neurodegenerative pathologies by slowing the progression of mental deterioration. In addition, ALC plays neuromodulatory effects on both synaptic morphology and synaptic transmission. These effects are likely due to affects of ALC through modulation of gene expression on several targets in the central nervous system. Here, we review the current state of knowledge on effects of ALC in the nervous system. PMID:27100509

  14. Fragrance material review on acetyl cedrene.

    Scognamiglio, J; Letizia, C S; Politano, V T; Api, A M

    2013-12-01

    A toxicologic and dermatologic review of acetyl cedrene when used as a fragrance ingredient is presented. Acetyl cedrene is a member of the fragrance structural group Alkyl Cyclic Ketones. The generic formula for this group can be represented as (R1)(R2)CO. These fragrances can be described as being composed of an alkyl, R1, and various substituted and bicyclic saturated or unsaturated cyclic hydrocarbons, R2, in which one of the rings may include up to 12 carbons. Alternatively, R2 may be a carbon bridge of C2-C4 carbon chain length between the ketone and cyclic hydrocarbon. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for acetyl cedrene were evaluated then summarized and includes physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, elicitation, phototoxicity, photoallergy, toxicokinetics, repeated dose, reproductive toxicity, and genotoxicity data. A safety assessment of the entire Alkyl Cyclic Ketones will be published simultaneously with this document; please refer to Belsito et al. (2013) (Belsito, D., Bickers, D., Bruze, M., Calow, P., Dagli, M., Fryer, A.D., Greim, H., Miyachi, Y., Saurat, J.H., Sipes, I.G., 2013. A Toxicologic and Dermatologic Assessment of Alkyl Cyclic Ketones When Used as Fragrance Ingredients. Submitted with this manuscript.) for an overall assessment of the safe use of this material and all Alkyl Cyclic Ketones in fragrances. PMID:23907023

  15. Biosynthesis and turnover of O-acetyl and N-acetyl groups in the gangliosides of human melanoma cells

    We and others previously described the melanoma-associated oncofetal glycosphingolipid antigen 9-O-acetyl-GD3, a disialoganglioside O-acetylated at the 9-position of the outer sialic acid residue. We have now developed methods to examine the biosynthesis and turnover of disialogangliosides in cultured melanoma cells and in Golgi-enriched vesicles from these cells. O-Acetylation was selectively expressed on di- and trisialogangliosides, but not on monosialogangliosides, nor on glycoprotein-bound sialic acids. Double-labeling of cells with [3H]acetate and [14C]glucosamine introduced easily detectable labels into each of the components of the ganglioside molecules. Pulse-chase studies of such doubly labeled molecules indicated that the O-acetyl groups turn over faster than the parent molecule. When Golgi-enriched vesicles from these cells were incubated with [acetyl-3H]acetyl-coenzyme A, the major labeled products were disialogangliosides. [Acetyl-3H]O-acetyl groups were found at both the 7- and the 9-positions, indicating that both 7-O-acetyl GD3 and 9-O-acetyl GD3 were synthesized by the action of O-acetyltransferase(s) on endogenous GD3. Analysis of the metabolically labeled molecules confirmed the existence of both 7- and 9-O-acetylated GD3 in the intact cells. Surprisingly, the major 3H-labeled product of the in vitro labeling reaction was not O-acetyl-GD3, but GD3, with the label exclusively in the sialic acid residues. Fragmentation of the labeled sialic acids by enzymatic and chemical methods showed that the 3H-label was exclusively in [3H]N-acetyl groups. Analyses of the double-labeled sialic acids from intact cells also showed that the 3H-label from [3H]acetate was exclusively in the form of [3H]N-acetyl groups, whereas the 14C-label was at the 4-position

  16. Acetylation phenotype variation in pediatric patients with atopic dermatitis

    Rafi A Majeed Al-Razzuqi

    2011-01-01

    Full Text Available Background: Few studies have been done on the relation between acetylator status and allergic diseases. Aim: To determine any possible association between acetylating phenotype in pediatric patients with atopic dermatitis (AD and the disease prognosis. Patients and Methods: Thirty-six pediatric patients and forty two healthy children as a control group were participated in the study. All participants received a single oral dose of dapsone of 1.54 mg/kg body weight, after an overnight fast. Using high performance liquid chromatography (HPLC, plasma concentrations of dapsone and its metabolite (monoacetyldapsone were estimated to phenotype the participants as slow and rapid acetylators according to their acetylation ratio (ratio of monoacetyldapsone to dapsone. Results: 72.2% of pediatric patients with AD showed slow acetylating status as compared to 69.4% of control individuals. Also, 73% of AD patients with slow acetylating phenotype had familial history of allergy. The severity of AD occurred only in slow acetylator patients. The eczematous lesions in slow acetylators presented mainly in the limbs, while in rapid acetylators, they were found mostly in face and neck. Conclusion: This study shows an association between the N-acetylation phenotype variation and clinical aspects of AD.

  17. Acetylation and characterization of spruce (Picea abies) galactoglucomannans.

    Xu, Chunlin; Leppänen, Ann-Sofie; Eklund, Patrik; Holmlund, Peter; Sjöholm, Rainer; Sundberg, Kenneth; Willför, Stefan

    2010-04-19

    Acetylated galactoglucomannans (GGMs) are the main hemicellulose type in most softwood species and can be utilized as, for example, bioactive polymers, hydrocolloids, papermaking chemicals, or coating polymers. Acetylation of spruce GGM using acetic anhydride with pyridine as catalyst under different conditions was conducted to obtain different degrees of acetylation on a laboratory scale, whereas, as a classic method, it can be potentially transferred to the industrial scale. The effects of the amount of catalyst and acetic anhydride, reaction time, temperature and pretreatment by acetic acid were investigated. A fully acetylated product was obtained by refluxing GGM for two hours. The structures of the acetylated GGMs were determined by SEC-MALLS/RI, (1)H and (13)C NMR and FTIR spectroscopy. NMR studies also indicated migration of acetyl groups from O-2 or O-3 to O-6 after a heating treatment in a water bath. The thermal stability of the products was investigated by DSC-TGA. PMID:20144827

  18. Preparation, physicochemical characterization and application of acetylated lotus rhizome starches.

    Sun, Suling; Zhang, Ganwei; Ma, Chaoyang

    2016-01-01

    Acetylated lotus rhizome starches were prepared, physicochemically characterized and used as food additives in puddings. The percentage content of the acetyl groups and degree of substitution increased linearly with the amount of acetic anhydride used. The introduction of acetyl groups was confirmed via Fourier transform infrared (FT-IR) spectroscopy. The values of the pasting parameters were lower for acetylated starch than for native starch. Acetylation was found to increase the light transmittance (%), the freeze-thaw stability, the swelling power and the solubility of the starch. Sensorial scores for puddings prepared using native and acetylated lotus rhizome starches as food additives indicated that puddings produced from the modified starches with superior properties over those prepared from native starch. PMID:26453845

  19. Obesity, cancer, and acetyl-CoA metabolism

    Lee, Joyce V.; Shah, Supriya A.; Wellen, Kathryn E.

    2013-01-01

    As rates of obesity soar in the Unites States and around the world, cancer attributed to obesity has emerged as major threat to public health. The link between obesity and cancer can be attributed in part to the state of chronic inflammation that develops in obesity. Acetyl-CoA production and protein acetylation patterns are highly sensitive to metabolic state and are significantly altered in obesity. In this article, we explore the potential role of nutrient-sensitive lysine acetylation in r...

  20. Getting a Knack for NAC: N-Acetyl-Cysteine

    Sansone, Randy A.; Sansone, Lori A.

    2011-01-01

    N-acetyl-cysteine, N-acetylcysteine, N-acetyl cysteine, and N-acetyl-L-cysteine are all designations for the same compound, which is abbreviated as NAC. NAC is a precursor to the amino acid cysteine, which ultimately plays two key metabolic roles. Through its metabolic contribution to glutathione production, cysteine participates in the general antioxidant activities of the body. Through its role as a modulator of the glutamatergic system, cysteine influences the reward-reinforcement pathway....

  1. Acetylation of Tau Inhibits Its Degradation and Contributes to Tauopathy

    Min, Sang-Won; Cho, Seo-Hyun; Zhou, Yungui; Schroeder, Sebastian; Haroutunian, Vahram; Seeley, William W.; Huang, Eric J.; Shen, Yong; Masliah, Eliezer; Mukherjee, Chandrani; Meyers, David; Cole, Philip A.; Ott, Melanie; Gan, Li

    2010-01-01

    Neurodegenerative tauopathies characterized by hyperphosphorylated tau include frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) and Alzheimer's disease (AD). Reducing tau levels improves cognitive function in mouse models of AD and FTDP-17, but the mechanisms regulating the turnover of pathogenic tau are unknown. We found that tau is acetylated and that tau acetylation prevents degradation of phosphorylated tau (p-tau). Using two antibodies specific for acetylated ta...

  2. Determination of amphetamine by HPLC after acetylation.

    Veress, T

    2000-01-01

    An analytical procedure has been developed for the HPLC determination of amphetamine by off-line pre-column derivatization. The proposed procedure consists of sample preparation by acetylation of amphetamine with acetic anhydride and a subsequent reversed-phase HPLC separation on an octadecyl silica stationary phase with salt-free mobile phase (tetrahydrofuran, acetonitrile, 0.1% triethylamine in water, 15:15:70 v/v) applying UV-detection. The applicability of the elaborated procedure is demonstrated with results obtained by analysis of real samples seized in the Hungarian black market. PMID:10641931

  3. Lipase-catalyzed synthesis of acetylated EGCG and antioxidant properties of the acetylated derivatives

    (-)-Epigallocatechin-3-O-gallate (EGCG) acetylated derivatives were prepared by lipase catalyzed acylation of EGCG with vinyl acetate to improve its lipophilicity and expand its application in lipophilic media. The immobilized lipase, Lipozyme RM IM, was found to be the optimum catalyst. The optimiz...

  4. Differential patterns of histone acetylation in inflammatory bowel diseases

    Adcock Ian M

    2011-01-01

    Full Text Available Abstract Post-translational modifications of histones, particularly acetylation, are associated with the regulation of inflammatory gene expression. We used two animal models of inflammation of the bowel and biopsy samples from patients with Crohn's disease (CD to study the expression of acetylated histones (H 3 and 4 in inflamed mucosa. Acetylation of histone H4 was significantly elevated in the inflamed mucosa in the trinitrobenzene sulfonic acid model of colitis particularly on lysine residues (K 8 and 12 in contrast to non-inflamed tissue. In addition, acetylated H4 was localised to inflamed tissue and to Peyer's patches (PP in dextran sulfate sodium (DSS-treated rat models. Within the PP, H3 acetylation was detected in the mantle zone whereas H4 acetylation was seen in both the periphery and the germinal centre. Finally, acetylation of H4 was significantly upregulated in inflamed biopsies and PP from patients with CD. Enhanced acetylation of H4K5 and K16 was seen in the PP. These results demonstrate that histone acetylation is associated with inflammation and may provide a novel therapeutic target for mucosal inflammation.

  5. Protein lysine acetylation in bacteria: Current state of the art.

    Ouidir, Tassadit; Kentache, Takfarinas; Hardouin, Julie

    2016-01-01

    Post-translational modifications of proteins are key events in cellular metabolism and physiology regulation. Lysine acetylation is one of the best studied protein modifications in eukaryotes, but, until recently, ignored in bacteria. However, proteomic advances have highlighted the diversity of bacterial lysine-acetylated proteins. The current data support the implication of lysine acetylation in various metabolic pathways, adaptation and virulence. In this review, we present a broad overview of the current knowledge of lysine acetylation in bacteria. We emphasize particularly the significant contribution of proteomics in this field. PMID:26390373

  6. Probing the acetylation code of histone H4.

    Lang, Diana; Schümann, Michael; Gelato, Kathy; Fischle, Wolfgang; Schwarzer, Dirk; Krause, Eberhard

    2013-10-01

    Histone modifications play crucial roles in genome regulation with lysine acetylation being implicated in transcriptional control. Here we report a proteome-wide investigation of the acetylation-dependent protein-protein interactions of the N-terminal tail of histone H4. Quantitative peptide-based affinity MS experiments using the SILAC approach determined the interactomes of H4 tails monoacetylated at the four known acetylation sites K5, K8, K12, and K16, bis-acetylated at K5/K12, triple-acetylated at K8/12/16 and fully tetra-acetylated. A set of 29 proteins was found enriched on the fully acetylated H4 tail while specific binders of the mono and bis-acetylated tails were barely detectable. These observations are in good agreement with earlier reports indicating that the H4 acetylation state establishes its regulatory effects in a cumulative manner rather than via site-specific recruitment of regulatory proteins. PMID:23970329

  7. Probing the acetylation code of histone H4.

    Lang, D; Schümann, M; Gelato, K.; Fischle, W; Schwarzer, D; Krause, E.

    2013-01-01

    Histone modifications play crucial roles in genome regulation with lysine acetylation being implicated in transcriptional control. Here we report a proteome-wide investigation of the acetylation-dependent protein–protein interactions of the N-terminal tail of histone H4. Quantitative peptide-based affinity MS experiments using the SILAC approach determined the interactomes of H4 tails monoacetylated at the four known acetylation sites K5, K8, K12, and K16, bis-acetylated at K5/K12, triple-ace...

  8. Reduced Wall Acetylation Proteins Play Vital and Distinct Roles in Cell Wall O-Acetylation in Arabidopsis

    Manabe, Yuzuki; Verhertbruggen, Yves; Gille, Sascha;

    2013-01-01

    The Reduced Wall Acetylation (RWA) proteins are involved in cell wall acetylation in plants. Previously, we described a single mutant, rwa2, which has about 20% lower level of O-acetylation in leaf cell walls and no obvious growth or developmental phenotype. In this study, we generated double...... quadruple rwa mutant can be completely complemented with the RWA2 protein expressed under 35S promoter, indicating the functional redundancy of the RWA proteins. Nevertheless, the degree of acetylation of xylan, (gluco) mannan, and xyloglucan as well as overall cell wall acetylation is affected differently...... in different combinations of triple mutants, suggesting their diversity in substrate preference. The overall degree of wall acetylation in the rwa quadruple mutant was reduced by 63% compared with the wild type, and histochemical analysis of the rwa quadruple mutant stem indicates defects in cell...

  9. Medial temporal N-acetyl-aspartate in pediatric major depression.

    MacMaster, Frank P; Moore, Gregory J; Russell, Aileen; Mirza, Yousha; Taormina, S Preeya; Buhagiar, Christian; Rosenberg, David R

    2008-10-30

    The medial temporal cortex (MTC) has been implicated in the pathogenesis of pediatric major depressive disorder (MDD). Eleven MDD case-control pairs underwent proton magnetic resonance spectroscopic imaging. N-acetyl-aspartate was lower in the left MTC (27%) in MDD patients versus controls. Lower N-acetyl-aspartate concentrations in MDD patients may reflect reduced neuronal viability. PMID:18703320

  10. Medial temporal N-acetyl aspartate in pediatric major depression

    MacMaster, Frank P.; Moore, Gregory J; Russell, Aileen; Mirza, Yousha; Taormina, S. Preeya; Buhagiar, Christian; Rosenberg, David R.

    2008-01-01

    The medial temporal cortex (MTC) has been implicated in the pathogenesis of pediatric major depressive disorder (MDD). Eleven MDD-case control pairs underwent proton magnetic resonance spectroscopic imaging. N-acetyl-aspartate was lower in left MTC (27%) in MDD patients versus controls. Lower N-acetyl-aspartate concentrations in MDD patients may reflect reduced neuronal viability. PMID:18703320

  11. Emerging Functions for N-Terminal Protein Acetylation in Plants

    Gibbs, Daniel J.

    2015-01-01

    N-terminal (Nt-) acetylation is a widespread but poorly understood co-translational protein modification. Two reports now shed light onto the proteome-wide dynamics and protein-specific consequences of Nt-acetylation in relation to plant development, stress-response, and protein stability, identifying this modification as a key regulator of diverse aspects of plant growth and behaviour.

  12. Antemortem stress regulates protein acetylation and glycolysis in postmortem muscle.

    Li, Zhongwen; Li, Xin; Wang, Zhenyu; Shen, Qingwu W; Zhang, Dequan

    2016-07-01

    Although exhaustive research has established that preslaughter stress is a major factor contributing to pale, soft, exudative (PSE) meat, questions remain regarding the biochemistry of postmortem glycolysis. In this study, the influence of preslaughter stress on protein acetylation in relationship to glycolysis was studied. The data show that antemortem swimming significantly enhanced glycolysis and the total acetylated proteins in postmortem longissimus dorsi (LD) muscle of mice. Inhibition of protein acetylation by histone acetyltransferase (HAT) inhibitors eliminated stress induced increase in glycolysis. Inversely, antemortem injection of histone deacetylase (HDAC) inhibitors, trichostatin A (TSA) and nicotinamide (NAM), further increased protein acetylation early postmortem and the glycolysis. These data provide new insight into the biochemistry of postmortem glycolysis by showing that protein acetylation regulates glycolysis, which may participate in the regulation of preslaughter stress on glycolysis in postmortem muscle. PMID:26920270

  13. Unchanged acetylation of isoniazid by alcohol intake

    Wilcke, J T R; Døssing, M; Angelo, H R;

    2004-01-01

    SETTING: In 10 healthy subjects, the influence of acute alcohol intake on the pharmacokinetics of isoniazid (INH) was studied. OBJECTIVE: To test the hypothesis that alcohol increases the conversion of INH by acetylation into its metabolite acetylisoniazid. DESIGN: In a crossover design, an oral...... dose of 300 mg INH was administered on 2 separate days, 14 days apart, with or without alcohol to a serum alcohol of about 21 mmol/l (1 g/l) maintained for 12 h. RESULTS: Neither the metabolism of INH nor that of acetylisoniazid was changed by acute alcohol intake. CONCLUSION: Acute alcohol intake has...... no impact on the conversion of INH to its metabolite acetylisoniazid, which is catalysed by the enzyme N-acetyltranferase. Accordingly, a metabolic effect of acute alcohol intake on INH metabolism probably contributes little to the therapeutic failure of anti-tuberculosis treatment among alcoholics....

  14. Role of acetyl CoA

    Existence of an acetyltransferase, which catalizes acetylation of deacetylcephalosporin C to cephalosporin C, was demonstrated for the first time in cell-free extracts of Cephalosporium acremonium. The pH optimum of the enzyme appeared to be 7.0 to 7.5 and the enzyme required essentially Mg2+ as a cofactor for its reaction. The activity of this enzyme was not observed in the cell-free extracts of deacetylcephalosporin C-producing mutants Nos. 20, 29, 36 and 40, but was recovered in a revertant obtained from the mutant No. 40. These results indicate that deacetylcephalosporin C accumulation by these mutants was due to the lack of the acetyltransferase and made it reasonable that the terminal reaction of cephalosporin C biosynthesis in Cephalosporium acremonium proceeded by the catalytic action of acetyltransferase. (auth.)

  15. The biology of lysine acetylation integrates transcriptional programming and metabolism

    Mujtaba Shiraz

    2011-03-01

    Full Text Available Abstract The biochemical landscape of lysine acetylation has expanded from a small number of proteins in the nucleus to a multitude of proteins in the cytoplasm. Since the first report confirming acetylation of the tumor suppressor protein p53 by a lysine acetyltransferase (KAT, there has been a surge in the identification of new, non-histone targets of KATs. Added to the known substrates of KATs are metabolic enzymes, cytoskeletal proteins, molecular chaperones, ribosomal proteins and nuclear import factors. Emerging studies demonstrate that no fewer than 2000 proteins in any particular cell type may undergo lysine acetylation. As described in this review, our analyses of cellular acetylated proteins using DAVID 6.7 bioinformatics resources have facilitated organization of acetylated proteins into functional clusters integral to cell signaling, the stress response, proteolysis, apoptosis, metabolism, and neuronal development. In addition, these clusters also depict association of acetylated proteins with human diseases. These findings not only support lysine acetylation as a widespread cellular phenomenon, but also impel questions to clarify the underlying molecular and cellular mechanisms governing target selectivity by KATs. Present challenges are to understand the molecular basis for the overlapping roles of KAT-containing co-activators, to differentiate between global versus dynamic acetylation marks, and to elucidate the physiological roles of acetylated proteins in biochemical pathways. In addition to discussing the cellular 'acetylome', a focus of this work is to present the widespread and dynamic nature of lysine acetylation and highlight the nexus that exists between epigenetic-directed transcriptional regulation and metabolism.

  16. Trichoderma reesei CE16 acetyl esterase and its role in enzymatic degradation of acetylated hemicellulose

    Biely, Peter; Cziszarava, Maria; Agger, Jane W.;

    2014-01-01

    Results The combined action of GH10 xylanase and acetylxylan esterases (AcXEs) leads to formation of neutral and acidic xylooligosaccharides with a few resistant acetyl groups mainly at their non-reducing ends. We show here that these acetyl groups serve as targets for TrCE16 AcE. The most promin...

  17. Acetylation/deacetylation reactions of T-2, acetyl T-2, HT-2, and acetyl HT-2 toxins in bovine rumen fluid in vitro

    Munger, C.E.; Ivie, G.W.; Christopher, R.J.; Hammock, B.D.; Phillips, T.D.

    A tritiated preparation of the trichothecene mycotoxin, T-2 toxin, underwent both acetylation and deacetylation reactions when incubated with bovine rumen fluid in vitro. Products from incubations of T-2 in rumen fluid included acetyl T-2, HT-2, and acetyl HT-2. Direct studies with tritiated samples of each of these metabolites confirmed their relatively facile interconversion in the rumen. Studies with (/sup 3/H)HT-2 under conditions of inhibited esterase activity (added diisopropyl fluorophosphate) showed that acetylation is preferred at C-3 vs. C-4. Studies with (/sup 3/H)acetyl T-2 indicated that deacetylation similarly occurs with greater rapidity at C-3. There were no indications that ester hydrolysis of these trichothecenes occurred at C-8 or C-15 or that they were subjected to epoxide reduction reactions. These data suggest that acetylation of T-2 and other trichothecenes in the rumen in situ may ultimately result in the absorption of more lipophilic metabolites whose toxicological and residual properties are at present unknown.

  18. Acetylation/deacetylation reactions of T-2, acetyl T-2, HT-2, and acetyl HT-2 toxins in bovine rumen fluid in vitro

    A tritiated preparation of the trichothecene mycotoxin, T-2 toxin, underwent both acetylation and deacetylation reactions when incubated with bovine rumen fluid in vitro. Products from incubations of T-2 in rumen fluid included acetyl T-2, HT-2, and acetyl HT-2. Direct studies with tritiated samples of each of these metabolites confirmed their relatively facile interconversion in the rumen. Studies with [3H]HT-2 under conditions of inhibited esterase activity (added diisopropyl fluorophosphate) showed that acetylation is preferred at C-3 vs. C-4. Studies with [3H]acetyl T-2 indicated that deacetylation similarly occurs with greater rapidity at C-3. There were no indications that ester hydrolysis of these trichothecenes occurred at C-8 or C-15 or that they were subjected to epoxide reduction reactions. These data suggest that acetylation of T-2 and other trichothecenes in the rumen in situ may ultimately result in the absorption of more lipophilic metabolites whose toxicological and residual properties are at present unknown

  19. Role of Histone Acetylation in Cell Cycle Regulation.

    Koprinarova, Miglena; Schnekenburger, Michael; Diederich, Marc

    2016-01-01

    Core histone acetylation is a key prerequisite for chromatin decondensation and plays a pivotal role in regulation of chromatin structure, function and dynamics. The addition of acetyl groups disturbs histone/DNA interactions in the nucleosome and alters histone/histone interactions in the same or adjacent nucleosomes. Acetyl groups can also provide binding sites for recruitment of bromodomain (BRD)-containing non-histone readers and regulatory complexes to chromatin allowing them to perform distinct downstream functions. The presence of a particular acetylation pattern influences appearance of other histone modifications in the immediate vicinity forming the "histone code". Although the roles of the acetylation of particular lysine residues for the ongoing chromatin functions is largely studied, the epigenetic inheritance of histone acetylation is a debated issue. The dynamics of local or global histone acetylation is associated with fundamental cellular processes such as gene transcription, DNA replication, DNA repair or chromatin condensation. Therefore, it is an essential part of the epigenetic cell response to processes related to internal and external signals. PMID:26303420

  20. Partially Acetylated Sugarcane Bagasse For Wicking Oil From Contaminated Wetlands

    Sugarcane bagasse was partially acetylated to enhance its oil-wicking ability in saturated environments while holding moisture for hydrocarbon biodegradation. The water sorption capacity of raw bagasse was reduced fourfold after treatment, which indicated considerably increased ...

  1. Acetylation of C/EBPα inhibits its granulopoietic function.

    Bararia, Deepak; Kwok, Hui Si; Welner, Robert S; Numata, Akihiko; Sárosi, Menyhárt B; Yang, Henry; Wee, Sheena; Tschuri, Sebastian; Ray, Debleena; Weigert, Oliver; Levantini, Elena; Ebralidze, Alexander K; Gunaratne, Jayantha; Tenen, Daniel G

    2016-01-01

    CCAAT/enhancer-binding protein alpha (C/EBPα) is an essential transcription factor for myeloid lineage commitment. Here we demonstrate that acetylation of C/EBPα at lysine residues K298 and K302, mediated at least in part by general control non-derepressible 5 (GCN5), impairs C/EBPα DNA-binding ability and modulates C/EBPα transcriptional activity. Acetylated C/EBPα is enriched in human myeloid leukaemia cell lines and acute myeloid leukaemia (AML) samples, and downregulated upon granulocyte-colony stimulating factor (G-CSF)- mediated granulocytic differentiation of 32Dcl3 cells. C/EBPα mutants that mimic acetylation failed to induce granulocytic differentiation in C/EBPα-dependent assays, in both cell lines and in primary hematopoietic cells. Our data uncover GCN5 as a negative regulator of C/EBPα and demonstrate the importance of C/EBPα acetylation in myeloid differentiation. PMID:27005833

  2. Function-structure relationships of acetylated pea starches

    J. Huang

    2006-01-01

    Cowpea, chickpea and yellow pea starches were studied and the results showed that their properties were strongly related to the chemical fine structures of the starches. Furthermore, granular starches were modified using two types of chemical acetylation reagents and then separated into different size fractions. The amount of introduced acetyl groups was found to depend on the size of the granules for the reaction with rapidly reacting reagent acetic acid anhydride, whereas the amount of intr...

  3. Acetyl radical generation in cigarette smoke: Quantification and simulations

    Hu, Na; Green, Sarah A.

    2014-10-01

    Free radicals are present in cigarette smoke and can have a negative effect on human health. However, little is known about their formation mechanisms. Acetyl radicals were quantified in tobacco smoke and mechanisms for their generation were investigated by computer simulations. Acetyl radicals were trapped from the gas phase using 3-amino-2, 2, 5, 5-tetramethyl-proxyl (3AP) on solid support to form stable 3AP adducts for later analysis by high-performance liquid chromatography (HPLC), mass spectrometry/tandem mass spectrometry (MS-MS/MS) and liquid chromatography-mass spectrometry (LC-MS). Simulations were performed using the Master Chemical Mechanism (MCM). A range of 10-150 nmol/cigarette of acetyl radical was measured from gas phase tobacco smoke of both commercial and research cigarettes under several different smoking conditions. More radicals were detected from the puff smoking method compared to continuous flow sampling. Approximately twice as many acetyl radicals were trapped when a glass fiber particle filter (GF/F specifications) was placed before the trapping zone. Simulations showed that NO/NO2 reacts with isoprene, initiating chain reactions to produce hydroxyl radical, which abstracts hydrogen from acetaldehyde to generate acetyl radical. These mechanisms can account for the full amount of acetyl radical detected experimentally from cigarette smoke. Similar mechanisms may generate radicals in second hand smoke.

  4. Site-specific acetylation of ISWI by GCN5

    Chioda Mariacristina

    2007-08-01

    Full Text Available Abstract Background The tight organisation of eukaryotic genomes as chromatin hinders the interaction of many DNA-binding regulators. The local accessibility of DNA is regulated by many chromatin modifying enzymes, among them the nucleosome remodelling factors. These enzymes couple the hydrolysis of ATP to disruption of histone-DNA interactions, which may lead to partial or complete disassembly of nucleosomes or their sliding on DNA. The diversity of nucleosome remodelling factors is reflected by a multitude of ATPase complexes with distinct subunit composition. Results We found further diversification of remodelling factors by posttranslational modification. The histone acetyltransferase GCN5 can acetylate the Drosophila remodelling ATPase ISWI at a single, conserved lysine, K753, in vivo and in vitro. The target sequence is strikingly similar to the N-terminus of histone H3, where the corresponding lysine, H3K14, can also be acetylated by GCN5. The acetylated form of ISWI represents a minor species presumably associated with the nucleosome remodelling factor NURF. Conclusion Acetylation of histone H3 and ISWI by GCN5 is explained by the sequence similarity between the histone and ISWI around the acetylation site. The common motif RKT/SxGx(KacxPR/K differs from the previously suggested GCN5/PCAF recognition motif GKxxP. This raises the possibility of co-regulation of a nucleosome remodelling factor and its nucleosome substrate through acetylation of related epitopes and suggests a direct crosstalk between two distinct nucleosome modification principles.

  5. A dysregulated acetyl/SUMO switch of FXR promotes hepatic inflammation in obesity

    Kim, Dong-Hyun; Xiao, Zhen; Kwon, Sanghoon; Sun, Xiaoxiao; Ryerson, Daniel; Tkac, David; Ma, Ping; Wu, Shwu-Yuan; Chiang, Cheng-Ming; Zhou, Edward; Xu, H. Eric; Palvimo, Jorma J; Chen, Lin-Feng; Kemper, Byron; Kemper, Jongsook Kim

    2014-01-01

    Acetylation of transcriptional regulators is normally dynamically regulated by nutrient status but is often persistently elevated in nutrient-excessive obesity conditions. We investigated the functional consequences of such aberrantly elevated acetylation of the nuclear receptor FXR as a model. Proteomic studies identified K217 as the FXR acetylation site in diet-induced obese mice. In vivo studies utilizing acetylation-mimic and acetylation-defective K217 mutants and gene expression profilin...

  6. Purification and properties of an O-acetyl-transferase from Escherichia coli that can O-acetylate polysialic acid sequences

    Certain strains of bacteria synthesize an outer polysialic acid (K1) capsule. Some strains of K1+ E.coli are also capable of adding O-acetyl-esters to the exocyclic hydroxyl groups of the sialic acid residues. Both the capsule and the O-acetyl modification have been correlated with differences in antigenicity and pathogenicity. The authors have developed an assay for an O-acetyl-transferase in E.coli that transfers O-[3H]acetyl groups from [3H]acetyl-Coenzyme A to colominic acid (fragments of the polysialic acid capsule). Using this assay, the enzyme was solubilized, and purified ∼ 600-fold using a single affinity chromatography step with Procion Red-A Agarose. The enzyme also binds to Coenzyme A Sepharose, and can be eluted with high salt or Coenzyme A. The partially purified enzyme has a pH optimum of 7.0 - 7.5, is unaffected by divalent cations, is inhibited by high salt concentrations, is inhibited by Coenzyme A (50% inhibition at 100 μM), and shows an apparent Km for colominic acid of 3.7 mM (sialic acid concentration). This enzyme could be involved in the O-acetyl +/- form variation seen in some strains of K1+ E.coli

  7. Histones of Chlamydomonas reinhardtii. Synthesis, acetylation, and methylation

    Histones of the green alga Chlamydomonas reinhardtii were prepared by a new method and fractionated by reversed-phase high-performance liquid chromatography. Acid-urea-Triton gel analysis and tritiated acetate labeling demonstrated high levels of steady-state acetylation for the single histone H3 protein, in contrast to low levels on histones H4 and H2B. Twenty percent of histone H3 is subject to dynamic acetylation with, on average, three acetylated lysine residues per protein molecule. Histone synthesis in light-dark-synchronized cultures was biphasic with pattern differences between two histone H1 variants, between two H2A variants, and between H2B and ubiquitinated H2B. Automated protein sequence analysis of histone H3 demonstrated a site-specific pattern of steady-state acetylation between 7 and 17% at five of the six amino-terminal lysines and of monomethylation between 5 and 81% at five of the eight amino-terminal lysines in a pattern that may limit dynamic acetylation. An algal histone H3 sequence was confirmed by protein sequencing with a since threonine as residue 28 instead of the serine(28)-alanine(29) sequence, present in all other known plant and animal H3 histones

  8. Curcumin-induced Histone Acetylation in Malignant Hematologic Cells

    Junbin HU; Yan WANG; Yan CHEN

    2009-01-01

    This study investigated the inhibitory effects of curcumin on proliferation of hemato-logical malignant cells in vitro and the anti-tumor mechanism at histone acetylation/histone deacety-lation levels.The effects of curcumin and histone deacetylase inhibitor trichostatin A (TSA) on the growth of Raji cells were tested by MTT assay.The expression of acetylated histone-3 (H3) in Raji,HL60 and K562 cells,and peripheral blood mononuclear cells (PBMCs) treated with curcumin or TSA was detected by immunohistochemistry and FACS.The results showed curcumin inhibited pro-liferation of Raji cells significantly in a time- and dose-dependent fashion,while exhibited low toxic-ity in PBMCs.Curcumin induced up-regulation of the expression of acetylated H3 dose-dependently in all malignant cell lines tested.In conclusion,curcumin inhibited proliferation of Raji cells selec-tively,enhanced the level of acetylated H3 in Raji,HL60,and K562 cells,which acted as a histone deacetylase inhibitor like TSA.Furthermore,up-regulation of H3 acetylation may play an important role in regulating the proliferation of Raji cells.

  9. Olig1 Acetylation and Nuclear Export Mediate Oligodendrocyte Development.

    Dai, Jinxiang; Bercury, Kathryn K; Jin, Weilin; Macklin, Wendy B

    2015-12-01

    The oligodendrocyte transcription factor Olig1 is critical for both oligodendrocyte development and remyelination in mice. Nuclear to cytoplasmic translocation of Olig1 protein occurs during brain development and in multiple sclerosis, but the detailed molecular mechanism of this translocation remains elusive. Here, we report that Olig1 acetylation and deacetylation drive its active translocation between the nucleus and the cytoplasm in both mouse and rat oligodendrocytes. We identified three functional nuclear export sequences (NES) localized in the basic helix-loop-helix domain and one specific acetylation site at Lys 150 (human Olig1) in NES1. Olig1 acetylation and deacetylation are regulated by the acetyltransferase CREB-binding protein and the histone deacetylases HDAC1, HDAC3, and HDAC10. Acetylation of Olig1 decreased its chromatin association, increased its interaction with inhibitor of DNA binding 2 and facilitated its retention in the cytoplasm of mature oligodendrocytes. These studies establish that acetylation of Olig1 regulates its chromatin dissociation and subsequent translocation to the cytoplasm and is required for its function in oligodendrocyte maturation. PMID:26631469

  10. H4K44 Acetylation Facilitates Chromatin Accessibility during Meiosis

    Jialei Hu

    2015-12-01

    Full Text Available Meiotic recombination hotspots are associated with histone post-translational modifications and open chromatin. However, it remains unclear how histone modifications and chromatin structure regulate meiotic recombination. Here, we identify acetylation of histone H4 at Lys44 (H4K44ac occurring on the nucleosomal lateral surface. We show that H4K44 is acetylated at pre-meiosis and meiosis and displays genome-wide enrichment at recombination hotspots in meiosis. Acetylation at H4K44 is required for normal meiotic recombination, normal levels of double-strand breaks (DSBs during meiosis, and optimal sporulation. Non-modifiable H4K44R results in increased nucleosomal occupancy around DSB hotspots. Our results indicate that H4K44ac functions to facilitate chromatin accessibility favorable for normal DSB formation and meiotic recombination.

  11. Recycling and Reuse of Ionic Liquid in Homogeneous Cellulose Acetylation

    HUANG Kelin; WU Rui; CAO Yan; LI Huiquan; WANG Jinshu

    2013-01-01

    Molecular distillation was used to recover ionic liquid (IL) 1-allyl-3-methylimidazolium chloride (AmimC1) in homogeneous cellulose acetylation.The five factors that affect the separation efficiency of molecular distillation,namely,feed flow rate,distillation temperature,feed temperature,wiper rotating speed,and distillation pressure,are discussed.The optimal recovery condition was determined via orthogonal experiments using an OA9(34) design.The IL was recycled and reused 5 times in the homogeneous cellulose acetylation system under optimal conditions.The purity of recycled IL the 5th time reached 99.56%.FT-IR (Fourier transform infrared spectroscopy) and 1H NMR (nuclear magnetic resonance) spectroscopy showed that the structure of the recovered IL is not changed.This work proves that AmirnCl has excellent reusability,and that molecular distillation is an effective method for recovering IL in homogeneous cellulose acetylation.

  12. Acetylation site specificities of lysine deacetylase inhibitors in human cells

    Schölz, Christian; Weinert, Brian Tate; Wagner, Sebastian A;

    2015-01-01

    Lysine deacetylases inhibitors (KDACIs) are used in basic research, and many are being investigated in clinical trials for treatment of cancer and other diseases. However, their specificities in cells are incompletely characterized. Here we used quantitative mass spectrometry (MS) to obtain...... acetylation signatures for 19 different KDACIs, covering all 18 human lysine deacetylases. Most KDACIs increased acetylation of a small, specific subset of the acetylome, including sites on histones and other chromatin-associated proteins. Inhibitor treatment combined with genetic deletion showed that the...

  13. Study on Reactions of 2-Acetyl-7-methylaminotropone with Pyridinecarboxyaldehydes

    GAO Wen-Tao; ZHENG Zhuo

    2003-01-01

    @@ Cinnamoyl group is a versatile constituent because of bearing active carbonyl group and α, β-unsaturated car bon-carbon double bond. A wide variety of heterocycle-fused troponoid compounds have been derived from cinnamoyl-substituted tropones. For examples, the 3-(4-aryl-3-cyano-2- methoxypyridin-6-yl)tropones were synthesized by the reactions of 2-acetyl-7-methylaminotropone with malononitrile via michael addition and cyclization. [1] There have been some reports about the synthesis of 2-cinnamoyl-7-methylaminotropone, [2,3] herein we further report the synthesis of this kind of compounds by the reactions of 2-acetyl-7-methylaminotropone with pyridinecarboxyaldehydes.

  14. New lysine-acetylated proteins screened by immunoaffinity and liquid chromatography-mass spectrometry

    2010-01-01

    The lack of selective extraction specific for lysine-acetylated proteins has been a major problem in the field of acetylation biology,though acetylation plays a key role in many biological processes.In this paper,we report for the first time the proteomic screening of lysine-acetylated proteins from a mouse liver tissue,by a new approach of immunoaffinity purification of lysine-acetylated peptides combined with nano-HPLC/MS/MS analysis.We have found 20 lysine-acetylated proteins with 21 lysine-acetylated sites,among which 12 lysine-acetylated proteins and 16 lysine-acetylated sites have never been reported before.Notably,three acetyltransferases harboring in mitochondrion are newly discovered acetyltransferases responsible for the acetylation of nonhistone proteins.We have explored the significant patterns of residue preference by the hierarchical clustering analysis of amino acid residues surrounding acetylation sites,which could be helpful to the prediction of new sites of lysine acetylation.Our findings provide more candidates for studying the important roles played by acetylation in diverse cellular pathways and related human diseases.

  15. Predicting post-translational lysine acetylation using support vector machines

    Gnad, Florian; Ren, Shubin; Choudhary, Chunaram;

    2010-01-01

    spectrometry to identify 3600 lysine acetylation sites on 1750 human proteins covering most of the previously annotated sites and providing the most comprehensive acetylome so far. This dataset should provide an excellent source to train support vector machines (SVMs) allowing the high accuracy in silico...

  16. The potential role of wood acetylation in climate change mitigation

    Van der Lugt, P.; Vogtländer, J.G.; Alexander, J.; Bongers, F.; Stebbins, H.

    2014-01-01

    In a carbon footprint assessment, the greenhouse gas emissions during the life cycle of a material can be measured, and compared to alternative products in terms of kg CO2 equivalent. If applied correctly, wood acetylation opens up a range of new innovative applications in which high performance yet

  17. Protein Acetylation Is Involved in Salmonella enterica Serovar Typhimurium Virulence.

    Sang, Yu; Ren, Jie; Ni, Jinjing; Tao, Jing; Lu, Jie; Yao, Yu-Feng

    2016-06-01

    Salmonella causes a range of diseases in different hosts, including enterocolitis and systemic infection. Lysine acetylation regulates many eukaryotic cellular processes, but its function in bacteria is largely unexplored. The acetyltransferase Pat and NAD(+)-dependent deacetylase CobB are involved in the reversible protein acetylation in Salmonella Typhimurium. Here, we used cell and animal models to evaluate the virulence of pat and cobB deletion mutants in S. Typhimurium and found that pat is critical for bacterial intestinal colonization and systemic infection. Next, to understand the underlying mechanism, genome-wide transcriptome was analyzed. RNA sequencing data showed that the expression of Salmonella pathogenicity island 1 (SPI-1) is partially dependent on pat In addition, we found that HilD, a key transcriptional regulator of SPI-1, is a substrate of Pat. The acetylation of HilD by Pat maintained HilD stability and was essential for the transcriptional activation of HilA. Taken together, these results suggest that a protein acetylation system regulates SPI-1 expression by controlling HilD in a posttranslational manner to mediate S. Typhimurium virulence. PMID:26810370

  18. Tubulin acetylation: responsible enzymes, biological functions and human diseases.

    Li, Lin; Yang, Xiang-Jiao

    2015-11-01

    Microtubules have important functions ranging from maintenance of cell morphology to subcellular transport, cellular signaling, cell migration, and formation of cell polarity. At the organismal level, microtubules are crucial for various biological processes, such as viral entry, inflammation, immunity, learning and memory in mammals. Microtubules are subject to various covalent modifications. One such modification is tubulin acetylation, which is associated with stable microtubules and conserved from protists to humans. In the past three decades, this reversible modification has been studied extensively. In mammals, its level is mainly governed by opposing actions of α-tubulin acetyltransferase 1 (ATAT1) and histone deacetylase 6 (HDAC6). Knockout studies of the mouse enzymes have yielded new insights into biological functions of tubulin acetylation. Abnormal levels of this modification are linked to neurological disorders, cancer, heart diseases and other pathological conditions, thereby yielding important therapeutic implications. This review summarizes related studies and concludes that tubulin acetylation is important for regulating microtubule architecture and maintaining microtubule integrity. Together with detyrosination, glutamylation and other modifications, tubulin acetylation may form a unique 'language' to regulate microtubule structure and function. PMID:26227334

  19. Acetylation regulates DNA repair mechanisms in human cells.

    Piekna-Przybylska, Dorota; Bambara, Robert A; Balakrishnan, Lata

    2016-06-01

    The p300-mediated acetylation of enzymes involved in DNA repair and replication has been previously shown to stimulate or inhibit their activities in reconstituted systems. To explore the role of acetylation on DNA repair in cells we constructed plasmid substrates carrying inactivating damages in the EGFP reporter gene, which should be repaired in cells through DNA mismatch repair (MMR) or base excision repair (BER) mechanisms. We analyzed efficiency of repair within these plasmid substrates in cells exposed to deacetylase and acetyltransferase inhibitors, and also in cells deficient in p300 acetyltransferase. Our results indicate that protein acetylation improves DNA mismatch repair in MMR-proficient HeLa cells and also in MMR-deficient HCT116 cells. Moreover, results suggest that stimulated repair of mismatches in MMR-deficient HCT116 cells is done though a strand-displacement synthesis mechanism described previously for Okazaki fragments maturation and also for the EXOI-independent pathway of MMR. Loss of p300 reduced repair of mismatches in MMR-deficient cells, but did not have evident effects on BER mechanisms, including the long patch BER pathway. Hypoacetylation of the cells in the presence of acetyltransferase inhibitor, garcinol generally reduced efficiency of BER of 8-oxoG damage, indicating that some steps in the pathway are stimulated by acetylation. PMID:27104361

  20. Surface effects in the acetylation of granular potato starch

    Steeneken, P.A.M.; Woortman, A.J.J.

    2008-01-01

    The occurrence of surface effects in the acetylation of granular potato starch with acetic anhydride to degrees of substitution 0.04-0.2 was studied by two different approaches. The first approach involved the fractionation of granular starch acetates into five different size classes and analysis of

  1. SCANDIUM TRIFLATE CATALYZED ACETYLATION OF STARCH UNDER MILD CONDITIONS

    Scandium (III) trifluoromethan sulfonate (Sc(OTf)3) was investigated as a catalyst for the acetylation of starch in order to determine the potential for preparing new types of starch esters under mild conditions. At room temperature, dry granular corn starch reacts with acetic anhydride in the pres...

  2. Enzymatic synthesis of carbon-11 N-acetyl-D-glucosamine

    An enzymatic synthesis of [11C] N-acetyl-D-glucosamine is described. 11CO2 is reacted with methylmagnesium bromide to form [1-11C]acetate. The latter is converted to [11C]acetylcoenzyme A by passage over an enzyme reactor containing immobilized acetylcoenzyme A synthetase, and to the title compound after purification. (author)

  3. DMPD: Acetylation of MKP-1 and the control of inflammation. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 18922786 Acetylation of MKP-1 and the control of inflammation. Chi H, Flavell RA. S...ci Signal. 2008 Oct 14;1(41):pe44. (.png) (.svg) (.html) (.csml) Show Acetylation of MKP-1 and the control of inflammation.... PubmedID 18922786 Title Acetylation of MKP-1 and the control of inflammation. Authors Chi H,

  4. The Acetyl Group Buffering Action of Carnitine Acetyltransferase Offsets Macronutrient-Induced Lysine Acetylation of Mitochondrial Proteins

    Michael N. Davies

    2016-01-01

    Full Text Available Lysine acetylation (AcK, a posttranslational modification wherein a two-carbon acetyl group binds covalently to a lysine residue, occurs prominently on mitochondrial proteins and has been linked to metabolic dysfunction. An emergent theory suggests mitochondrial AcK occurs via mass action rather than targeted catalysis. To test this hypothesis, we performed mass spectrometry-based acetylproteomic analyses of quadriceps muscles from mice with skeletal muscle-specific deficiency of carnitine acetyltransferase (CrAT, an enzyme that buffers the mitochondrial acetyl-CoA pool by converting short-chain acyl-CoAs to their membrane permeant acylcarnitine counterparts. CrAT deficiency increased tissue acetyl-CoA levels and susceptibility to diet-induced AcK of broad-ranging mitochondrial proteins, coincident with diminished whole body glucose control. Sub-compartment acetylproteome analyses of muscles from obese mice and humans showed remarkable overrepresentation of mitochondrial matrix proteins. These findings reveal roles for CrAT and L-carnitine in modulating the muscle acetylproteome and provide strong experimental evidence favoring the nonenzymatic carbon pressure model of mitochondrial AcK.

  5. The Acetyl Group Buffering Action of Carnitine Acetyltransferase Offsets Macronutrient-Induced Lysine Acetylation of Mitochondrial Proteins.

    Davies, Michael N; Kjalarsdottir, Lilja; Thompson, J Will; Dubois, Laura G; Stevens, Robert D; Ilkayeva, Olga R; Brosnan, M Julia; Rolph, Timothy P; Grimsrud, Paul A; Muoio, Deborah M

    2016-01-12

    Lysine acetylation (AcK), a posttranslational modification wherein a two-carbon acetyl group binds covalently to a lysine residue, occurs prominently on mitochondrial proteins and has been linked to metabolic dysfunction. An emergent theory suggests mitochondrial AcK occurs via mass action rather than targeted catalysis. To test this hypothesis, we performed mass spectrometry-based acetylproteomic analyses of quadriceps muscles from mice with skeletal muscle-specific deficiency of carnitine acetyltransferase (CrAT), an enzyme that buffers the mitochondrial acetyl-CoA pool by converting short-chain acyl-CoAs to their membrane permeant acylcarnitine counterparts. CrAT deficiency increased tissue acetyl-CoA levels and susceptibility to diet-induced AcK of broad-ranging mitochondrial proteins, coincident with diminished whole body glucose control. Sub-compartment acetylproteome analyses of muscles from obese mice and humans showed remarkable overrepresentation of mitochondrial matrix proteins. These findings reveal roles for CrAT and L-carnitine in modulating the muscle acetylproteome and provide strong experimental evidence favoring the nonenzymatic carbon pressure model of mitochondrial AcK. PMID:26748706

  6. 2-Acetylthiamin pyrophosphate (acetyl-TPP) pH-rate profile for hydrolysis of acetyl-TPP and isolation of acetyl-TPP as a transient species in pyruvate dehydrogenase catalyzed reactions

    Rate constants for the hydrolysis of acetyl-TPP were measured pH values of 2.5 and 7.5 and plotted as log kobs versus pH. The pH-rate profile defined two legs, each with a slope of +1 but separated by a region of decreased slope between pH 4 and pH 6. The rates were insensitive to buffer concentrations. Each leg of the profile reflected specific-base-catalyzed hydrolysis of acetyl-TPP, analogous to the hydrolysis of 2-acetyl-3,4-dimethylthiazolium ion. The separation of the two legs of this profile has been shown to be caused by the ionization of a group exhibiting a pKa of 4.73 within acetyl-TPP that is remote from the acetyl group, the aminopyrimidine ring, which is promoted below pH 4.73. The protonation level of this ring has been shown to control the equilibrium partitioning of acetyl-TPP among its carbinolamine, keto, and hydrate forms. The differential partitioning of these species is a major factor causing the separation between the two legs of the pH-rate profile. The characteristic pH-rate profile and the availability of synthetic acetyl-TPP have facilitated the isolation and identification of [1-14C]acetyl-TPP from acid-quenched enymatic reaction mixtures at steady states. [1-14C]Acetyl-TPP was identified as a transient species in reactions catalyzed by the PDH complex or the pyruvate dehydrogenase component of the complex (E1). The pH-rate profile for hydrolysis of [1-14C]-acetyl-TPP, isolated from enzymatic reactions was found to be indistinguishable from that for authentic acetyl-TPP, which constituted positive identification of the 14C-labeled enzymic species

  7. Histone H3 acetylation in the postmortem Parkinson's disease primary motor cortex.

    Gebremedhin, Kibrom G; Rademacher, David J

    2016-08-01

    Although the role of epigenetics in Parkinson's disease (PD) has not been extensively studied, α-synuclein, the main component of Lewy bodies, decreased histone H3 acetylation. Here, we determined if there were histone acetylation changes in the primary motor cortex which, according to the Braak model, is one of the last brain regions affected in PD. Net histone H3 acetylation, histone H3 lysine 9 (H3K9), histone H3 lysine 14 (H3K14), histone H3 lysine 18 (H3K18), and histone H3 lysine 23 (H3K23) acetylation was assessed in the primary motor cortex of those affected and unaffected by PD. There was net increase in histone H3 acetylation due to increased H3K14 and H3K18 acetylation. There was a decrease in H3K9 acetylation. No between-groups difference was detected in H3K23 acetylation. Relationships between Unified Lewy Body Staging scores and histone H3 acetylation and substantia nigra depigmentation scores and histone H3 acetylation were observed. No relationships were detected between postmortem interval and histone H3 acetylation and expired age and histone H3 acetylation. These correlational data support the notion that the histone H3 acetylation changes observed here are not due to the postmortem interval or aging. Instead, they are due to PD and/or factors that covary with PD. The data suggest enhanced gene transcription in the primary motor cortex of the PD brain due to increase H3K14 and H3K18 acetylation. This effect is partially offset by a decreased H3K9 acetylation, which might repress gene transcription. PMID:27241718

  8. Altered acetylation and succinylation profiles in Corynebacterium glutamicum in response to conditions inducing glutamate overproduction.

    Mizuno, Yuta; Nagano-Shoji, Megumi; Kubo, Shosei; Kawamura, Yumi; Yoshida, Ayako; Kawasaki, Hisashi; Nishiyama, Makoto; Yoshida, Minoru; Kosono, Saori

    2016-02-01

    The bacterium Corynebacterium glutamicum is utilized during industrial fermentation to produce amino acids such as l-glutamate. During l-glutamate fermentation, C. glutamicum changes the flux of central carbon metabolism to favor l-glutamate production, but the molecular mechanisms that explain these flux changes remain largely unknown. Here, we found that the profiles of two major lysine acyl modifications were significantly altered upon glutamate overproduction in C. glutamicum; acetylation decreased, whereas succinylation increased. A label-free semi-quantitative proteomic analysis identified 604 acetylated proteins with 1328 unique acetylation sites and 288 succinylated proteins with 651 unique succinylation sites. Acetylation and succinylation targeted enzymes in central carbon metabolic pathways that are directly related to glutamate production, including the 2-oxoglutarate dehydrogenase complex (ODHC), a key enzyme regulating glutamate overproduction. Structural mapping revealed that several critical lysine residues in the ODHC components were susceptible to acetylation and succinylation. Furthermore, induction of glutamate production was associated with changes in the extent of acetylation and succinylation of lysine, suggesting that these modifications may affect the activity of enzymes involved in glutamate production. Deletion of phosphotransacetylase decreased the extent of protein acetylation in nonproducing condition, suggesting that acetyl phosphate-dependent acetylation is active in C. glutamicum. However, no effect was observed on the profiles of acetylation and succinylation in glutamate-producing condition upon disruption of acetyl phosphate metabolism or deacetylase homologs. It was considered likely that the reduced acetylation in glutamate-producing condition may reflect metabolic states where the flux through acid-producing pathways is very low, and substrates for acetylation do not accumulate in the cell. Succinylation would occur more

  9. Specificity of antibodies to O-acetyl-positive and O-acetyl-negative group C meningococcal polysaccharides in sera from vaccinees and carriers.

    Arakere, G; Frasch, C E

    1991-01-01

    Most group C Neisseria meningitidis strains produce an O-acetyl-positive polysaccharide, a homopolymer of alpha-2----9-linked N-acetylneuraminic acid with O-acetyl groups at the C-7 and C-8 of its sialic acid residues. The majority of disease isolates have been reported to contain this polysaccharide. Some strains produce group C polysaccharide lacking O-acetyl groups. The licensed vaccine contains the O-acetyl-positive polysaccharide. We have measured the antibody specificities to the two po...

  10. Proteomic analysis of lysine acetylation sites in rat tissues reveals organ specificity and subcellular patterns

    Lundby, Alicia; Hansen, Kasper Lage; Weinert, Brian Tate; Breinholt Bekker-Jensen, Dorte; Secher, Anna; Skovgaard, Tine; Kelstrup, Christian; Dmytriyev, Anatoliy; Choudhary, Chuna Ram; Lundby, Carsten; Olsen, Jesper Velgaard

    2012-01-01

    Lysine acetylation is a major posttranslational modification involved in a broad array of physiological functions. Here, we provide an organ-wide map of lysine acetylation sites from 16 rat tissues analyzed by high-resolution tandem mass spectrometry. We quantify 15,474 modification sites on 4...... subcellular acetylation distribution is tissue-type dependent and that acetylation targets tissue-specific pathways involved in fundamental physiological processes. We compare lysine acetylation patterns for rat as well as human skeletal muscle biopsies and demonstrate its general involvement in muscle...

  11. The growing landscape of lysine acetylation links metabolism and cell signalling

    Choudhary, Chuna Ram; Weinert, Brian Tate; Nishida, Yuya;

    2014-01-01

    Lysine acetylation is a conserved protein post-translational modification that links acetyl-coenzyme A metabolism and cellular signalling. Recent advances in the identification and quantification of lysine acetylation by mass spectrometry have increased our understanding of lysine acetylation......, implicating it in many biological processes through the regulation of protein interactions, activity and localization. In addition, proteins are frequently modified by other types of acylations, such as formylation, butyrylation, propionylation, succinylation, malonylation, myristoylation, glutarylation and...... deacylating enzymes and also highlight the mechanisms by which acetylation regulates various cellular processes....

  12. Ubiquitination of Notch1 is regulated by MAML1-mediated p300 acetylation of Notch1

    Popko-Scibor, Anita E.; Lindberg, Mikael J.; Hansson, Magnus L.; Holmlund, Teresa [Division of Molecular Toxicology, Institute of Environmental Medicine, Karolinska Institutet, 171 77 Stockholm (Sweden); Wallberg, Annika E., E-mail: Annika.Wallberg@ki.se [Division of Molecular Toxicology, Institute of Environmental Medicine, Karolinska Institutet, 171 77 Stockholm (Sweden)

    2011-12-16

    Highlights: Black-Right-Pointing-Pointer p300 acetylates conserved lysines within Notch1 C-terminal nuclear localization signal. Black-Right-Pointing-Pointer MAML1 and CSL, components of Notch transcription complex, increase Notch acetylation. Black-Right-Pointing-Pointer MAML1-dependent acetylation of Notch1 by p300 decreases the ubiquitination of Notch1. Black-Right-Pointing-Pointer CDK8 inhibits Notch acetylation and Notch transcription enhanced by p300. -- Abstract: Earlier studies demonstrated the involvement of the p300 histone acetyltransferase in Notch signaling but the precise mechanisms by which p300 might modulate Notch function remains to be investigated. In this study, we show that p300 acetylates Notch1 ICD in cell culture assay and in vitro, and conserved lysines located within the Notch C-terminal nuclear localization signal are essential for Notch acetylation. MAML1 and CSL, which are components of the Notch transcription complex, enhance Notch acetylation and we suggest that MAML1 increases Notch acetylation by potentiating p300 autoacetylation. Furthermore, MAML1-dependent acetylation of Notch1 ICD by p300 decreases the ubiquitination of Notch1 ICD in cellular assays. CDK8 has been shown to target Notch1 for ubiquitination and proteosomal degradation. We show that CDK8 inhibits Notch acetylation and Notch transcription enhanced by p300. Therefore, we speculate that acetylation of Notch1 might be a mechanism to regulate Notch activity by interfering with ubiquitin-dependent pathways.

  13. N-Acetyltransferase 2 (NAT2) in Tunisian Population: Correlation Between Acetylation Phenotype and Genotype

    One hundred tuberculous patients were studied during 2004-2005 to determine acetylation phenotype, frequent mutations of NAT2 gene and to compare acetylation phenotype with NAT2 genotype in Tunisian population. Acetylation phenotype was determined by determination of acetylation index. Five mutations of NAT2 gene were evaluated by PCR/RFLP. Results show bimodal distribution of acetylation SA and RA phenotype, 75% and 25% and genotype 56% and 44%, respectively. Ten NAT2 alleles were found, NAT2*4 being the major one. Thirty-two different genotypes were found (9 RA and 23 SA). The major one was NAT2*6 B/NAT2*4. The concordance value was 79%. A good sensibility (98, 2%) of acetylation test for SA detection was found. Thus, acetylation phenotype in SA is predicted with poor error risk. (author)

  14. Lysine acetylation targets protein complexes and co-regulates major cellular functions

    Choudhary, Chuna Ram; Kumar, Chanchal; Gnad, Florian; Nielsen, Michael L; Rehman, Michael; Walther, Tobias C; Olsen, Jesper V; Mann, Matthias

    2009-01-01

    Lysine acetylation is a reversible posttranslational modification of proteins and plays a key role in regulating gene expression. Technological limitations have so far prevented a global analysis of lysine acetylation's cellular roles. We used high-resolution mass spectrometry to identify 3600...... lysine acetylation sites on 1750 proteins and quantified acetylation changes in response to the deacetylase inhibitors suberoylanilide hydroxamic acid and MS-275. Lysine acetylation preferentially targets large macromolecular complexes involved in diverse cellular processes, such as chromatin remodeling......, cell cycle, splicing, nuclear transport, and actin nucleation. Acetylation impaired phosphorylation-dependent interactions of 14-3-3 and regulated the yeast cyclin-dependent kinase Cdc28. Our data demonstrate that the regulatory scope of lysine acetylation is broad and comparable with that of other...

  15. Chemical Genetics of Acetyl-CoA Carboxylases

    Xuyu Zu

    2013-01-01

    Full Text Available Chemical genetic studies on acetyl-CoA carboxylases (ACCs, rate-limiting enzymes in long chain fatty acid biosynthesis, have greatly advanced the understanding of their biochemistry and molecular biology and promoted the use of ACCs as targets for herbicides in agriculture and for development of drugs for diabetes, obesity and cancers. In mammals, ACCs have both biotin carboxylase (BC and carboxyltransferase (CT activity, catalyzing carboxylation of acetyl-CoA to malonyl-CoA. Several classes of small chemicals modulate ACC activity, including cellular metabolites, natural compounds, and chemically synthesized products. This article reviews chemical genetic studies of ACCs and the use of ACCs for targeted therapy of cancers.

  16. Use of Intravenous N-Acetyl Systein in Paracetamol Intoxication

    Latif Duran; Bülent Şişman; Canan Doğruel; Türker Yardan; Ahmet Baydın; Yücel Yavuz

    2011-01-01

    Objective: In this study, we aimed to present our clinical experiences of intravenous (IV) N-Acetyl cystein administration in patients admitted to our emergency department with paracetamol intoxication.Material and Methods: This study was conducted between January 2007 and December 2009, in the Ondokuz Mayis University Medical Faculty Hospital, Emergency Service, and the hospital records of adult patients admitted with paracetamol poisoning were examined retrospectively. Fifty three patients ...

  17. The potential role of wood acetylation in climate change mitigation

    Van der Lugt, P.; Vogtländer, J.G.; J. Alexander; Bongers, F.; Stebbins, H.

    2014-01-01

    In a carbon footprint assessment, the greenhouse gas emissions during the life cycle of a material can be measured, and compared to alternative products in terms of kg CO2 equivalent. If applied correctly, wood acetylation opens up a range of new innovative applications in which high performance yet carbon intensive non-renewable materials such as metals, plastics and concrete may be replaced by abundantly available nondurable wood species. To better understand the difference in greenhouse ga...

  18. Acetylation modification regulates GRP78 secretion in colon cancer cells.

    Li, Zongwei; Zhuang, Ming; Zhang, Lichao; Zheng, Xingnan; Yang, Peng; Li, Zhuoyu

    2016-01-01

    High glucose-regulated protein 78 (GRP78) expression contributes to the acquisition of a wide range of phenotypic cancer hallmarks, and the pleiotropic oncogenic functions of GRP78 may result from its diverse subcellular distribution. Interestingly, GRP78 has been reported to be secreted from solid tumour cells, participating in cell-cell communication in the tumour microenvironment. However, the mechanism underlying this secretion remains elusive. Here, we report that GRP78 is secreted from colon cancer cells via exosomes. Histone deacetylase (HDAC) inhibitors blocked GRP78 release by inducing its aggregation in the ER. Mechanistically, HDAC inhibitor treatment suppressed HDAC6 activity and led to increased GRP78 acetylation; acetylated GRP78 then bound to VPS34, a class III phosphoinositide-3 kinase, consequently preventing the sorting of GRP78 into multivesicular bodies (MVBs). Of note, we found that mimicking GRP78 acetylation by substituting the lysine at residue 633, one of the deacetylated sites of HDAC6, with a glutamine resulted in decreased GRP78 secretion and impaired tumour cell growth in vitro. Our study thus reveals a hitherto-unknown mechanism of GRP78 secretion and may also provide implications for the therapeutic use of HDAC inhibitors. PMID:27460191

  19. Acetylation modification regulates GRP78 secretion in colon cancer cells

    Li, Zongwei; Zhuang, Ming; Zhang, Lichao; Zheng, Xingnan; Yang, Peng; Li, Zhuoyu

    2016-01-01

    High glucose-regulated protein 78 (GRP78) expression contributes to the acquisition of a wide range of phenotypic cancer hallmarks, and the pleiotropic oncogenic functions of GRP78 may result from its diverse subcellular distribution. Interestingly, GRP78 has been reported to be secreted from solid tumour cells, participating in cell-cell communication in the tumour microenvironment. However, the mechanism underlying this secretion remains elusive. Here, we report that GRP78 is secreted from colon cancer cells via exosomes. Histone deacetylase (HDAC) inhibitors blocked GRP78 release by inducing its aggregation in the ER. Mechanistically, HDAC inhibitor treatment suppressed HDAC6 activity and led to increased GRP78 acetylation; acetylated GRP78 then bound to VPS34, a class III phosphoinositide-3 kinase, consequently preventing the sorting of GRP78 into multivesicular bodies (MVBs). Of note, we found that mimicking GRP78 acetylation by substituting the lysine at residue 633, one of the deacetylated sites of HDAC6, with a glutamine resulted in decreased GRP78 secretion and impaired tumour cell growth in vitro. Our study thus reveals a hitherto-unknown mechanism of GRP78 secretion and may also provide implications for the therapeutic use of HDAC inhibitors. PMID:27460191

  20. Astrocyte Reactivity Following Blast Exposure Involves Aberrant Histone Acetylation

    Bailey, Zachary S.; Grinter, Michael B.; VandeVord, Pamela J.

    2016-01-01

    Blast induced neurotrauma (BINT) is a prevalent injury within military and civilian populations. The injury is characterized by persistent inflammation at the cellular level which manifests as a multitude of cognitive and functional impairments. Epigenetic regulation of transcription offers an important control mechanism for gene expression and cellular function which may underlie chronic inflammation and result in neurodegeneration. We hypothesize that altered histone acetylation patterns may be involved in blast induced inflammation and the chronic activation of glial cells. This study aimed to elucidate changes to histone acetylation occurring following injury and the roles these changes may have within the pathology. Sprague Dawley rats were subjected to either a 10 or 17 psi blast overpressure within an Advanced Blast Simulator (ABS). Sham animals underwent the same procedures without blast exposure. Memory impairments were measured using the Novel Object Recognition (NOR) test at 2 and 7 days post-injury. Tissues were collected at 7 days for Western blot and immunohistochemistry (IHC) analysis. Sham animals showed intact memory at each time point. The novel object discrimination decreased significantly between two and 7 days for each injury group (p processes. We have shown aberrant histone acetylation patterns involved in blast induced astrogliosis and cognitive impairments. Further understanding of their role in the injury progression may lead to novel therapeutic targets. PMID:27551260

  1. Histone acetylation regulates osteodifferentiation of hDPSCs via DSPP.

    Gu, Shensheng; Liang, Jingping; Wang, Jia; Liu, Bin

    2013-01-01

    Dental pulp stem cells (DPSCs) are a unique population of precursor cells isolated from postnatal human dental pulp, with the ability to regenerate a reparative dentin-like complex. We examined the regulation of odontoblast-like differentiation of DPSCs by histone acetylation. Western blot analysis showed that histone H3 acetylation was strongly induced in osteodifferentiation medium. Inhibition of histone acetyltransferase by garcinol reversed osteodifferentiation and mineral formation. Real-time polymerase chain reaction assay indicated that the dentin sialophosphoprotein (DSPP) gene, which is mainly expressed in odontoblasts and preameloblasts in teeth and plays an important role in tooth function, was also down-regulated in garcinol-treated cells. Moreover, lentivirus-mediated knockdown of DSPP in human DPSCs was associated with significant inhibition of mineral formation, but not osteoblast differentiation. In conclusion, the results of this study suggest that DSPP positively affects mineral formation, and that odontoblast-like differentiation and maturation of DPSCs can be regulated by histone acetylation of the DSPP gene. PMID:23747867

  2. Selective cleavage enhanced by acetylating the side chain of lysine.

    Fu, Leixiaomeng; Chen, Tingting; Xue, Gaiqing; Zu, Lily; Fang, Weihai

    2013-01-01

    Selective cleavage is of great interest in mass spectrometry studies as it can help sequence identification by promoting simple fragmentation pattern of peptides and proteins. In this work, the collision-induced dissociation of peptides containing internal lysine and acetylated lysine residues were studied. The experimental and computational results revealed that multiple fragmentation pathways coexisted when the lysine residue was two amino acid residues away from N-terminal of the peptide. After acetylation of the lysine side-chain, b(n)+ ions were the most abundant primary fragment products and the Lys(Ac)-Gly amide bond became the dominant cleavage site via an oxazolone pathway. Acetylating the side-chain of lysine promoted the selective cleavage of Lys-Xxx amide bond and generated much more information of the peptide backbone sequence. The results re-evaluate the selective cleavage due to the lysine basic side-chain and provide information for studying the post-translational modification of proteins and other bio-molecules containing Lys residues. PMID:23303756

  3. Acetylator genotype-dependent formation of 2-aminofluorene-hemoglobin adducts in rapid and slow acetylator Syrian hamsters congenic at the NAT2 locus.

    Feng, Y; Rustan, T D; Ferguson, R J; Doll, M A; Hein, D W

    1994-01-01

    Arylamine-hemoglobin adducts are a valuable dosimeter for assessing arylamine exposures and carcinogenic risk. The effects of age, sex, time-course, dose, and acetylator genotype on levels of 2-aminofluorene-hemoglobin adducts were investigated in homozygous rapid (Bio. 82.73/H-Patr) and slow (Bio. 82.73/H-Pats) acetylator hamsters congenic at the polymorphic (NAT2) acetylator locus. Following administration of a single ip dose of [3H]2-aminofluorene, peak 2-aminofluorene-hemoglobin adduct levels were achieved at 12-18 hr and retained a plateau up to 72 hr postinjection in both rapid and slow acetylator congenic hamsters. 2-Aminofluorene-hemoglobin adduct levels did not differ significantly between young (5-6 weeks) and old (32-49 weeks) hamsters or between male and female hamsters within either acetylator genotype. 2-Aminofluorene-hemoglobin adduct levels increased in a dose-dependent manner (r = 0.95, p = 0.0001) and were consistently higher in slow versus rapid acetylator congenic hamsters in studies of both time-course and dose-effect. The magnitude of the acetylator genotype-dependent difference was a function of dose; 2-aminofluorene-hemoglobin adduct levels were 1.5-fold higher in slow acetylator congenic hamsters following a 60 mg/kg 2-aminofluorene dose (p = 0.0013) but 2-fold higher following a 100 mg/kg 2-aminofluorene dose (p < 0.0001). These results show a specific and significant role for NAT2 acetylator genotype in formation of arylamine-hemoglobin adducts, which may reflect the relationship between acetylator genotype and the incidence of different cancers from arylamine exposures. PMID:8291051

  4. Acetylated starch nanocrystals: Preparation and antitumor drug delivery study.

    Xiao, Huaxi; Yang, Tao; Lin, Qinlu; Liu, Gao-Qiang; Zhang, Lin; Yu, Fengxiang; Chen, Yuejiao

    2016-08-01

    In this study, we developed a new nanoparticulate system for acetylated starch nanocrystals (ASN) using broken rice. ASN with different degrees of substitution (DS) of 0.04, 0.08 and 0.14 were prepared using acetic anhydride as acetylating agent through reaction with starch nanocrystals (SN). The resulting ASN were investigated for the capability to load and release doxorubicin hydrochloride (DOX), and the antitumor activities of DOX-loaded SN and DOX-loaded ASN were evaluated as potential drug delivery systems for cancer therapy. Cellular uptake and cytotoxicity of nanocrystals and the DOX-loaded nanocrystals were investigated using fluorescence microscopy and a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay. Compared with acetylated starches (AS) and native starches (NS), ASN with DS 0.14 loaded up to 6.07% of DOX with a higher loading efficiency of 91.1% and had steadier drug-release rates. Toxicity analysis using the rat hepatocytes model suggested that ASN was biocompatible and could be used for drug delivery. Furthermore, ASN were taken up by cancer cells in vitro and significantly enhanced the cytotoxicity of DOX against HeLa human cervical carcinoma cells. The IC50 value of DOX-loaded ASN-DS 0.14 was 3.8μg/mL for 24h of treatment, which was significantly lower than that of free DOX (21μg/mL). These results indicate that the prepared ASN using broken rice is a promising vehicle for the controlled delivery of DOX for cancer therapy. PMID:27156696

  5. Acetyl hexapeptide-3 in a cosmetic formulation acts on skin mechanical properties - clinical study

    Kassandra Azevedo Tadini; Daiane Garcia Mercurio; Patrícia Maria Berardo Gonçalves Maia Campos

    2015-01-01

    abstract Acetyl hexapeptide-3 has been used in anti-aging topical formulations aimed at improving skin appearance. However, few basic studies address its effects on epidermis and dermis, when vehiculated in topical formulations. Thus, the objective of this study was to determine the clinical efficacy of acetyl hexapeptide-3 using biophysical techniques. For this purpose, formulations with and without acetyl hexapeptide-3 were applied to the ventral forearm and the face area of forty female vo...

  6. Autoimmune regulator is acetylated by transcription coactivator CBP/p300

    Saare, Mario, E-mail: mario.saare@ut.ee [Molecular Pathology, Institute of General and Molecular Pathology, University of Tartu, 19th Ravila Str, Tartu (Estonia); Rebane, Ana [Molecular Pathology, Institute of General and Molecular Pathology, University of Tartu, 19th Ravila Str, Tartu (Estonia); SIAF, Swiss Institute of Allergy and Asthma Research, University of Zuerich, Davos (Switzerland); Rajashekar, Balaji; Vilo, Jaak [BIIT, Bioinformatics, Algorithmics and Data Mining group, Institute of Computer Science, University of Tartu, Tartu (Estonia); Peterson, Paert [Molecular Pathology, Institute of General and Molecular Pathology, University of Tartu, 19th Ravila Str, Tartu (Estonia)

    2012-08-15

    The Autoimmune Regulator (AIRE) is a regulator of transcription in the thymic medulla, where it controls the expression of a large set of peripheral-tissue specific genes. AIRE interacts with the transcriptional coactivator and acetyltransferase CBP and synergistically cooperates with it in transcriptional activation. Here, we aimed to study a possible role of AIRE acetylation in the modulation of its activity. We found that AIRE is acetylated in tissue culture cells and this acetylation is enhanced by overexpression of CBP and the CBP paralog p300. The acetylated lysines were located within nuclear localization signal and SAND domain. AIRE with mutations that mimicked acetylated K243 and K253 in the SAND domain had reduced transactivation activity and accumulated into fewer and larger nuclear bodies, whereas mutations that mimicked the unacetylated lysines were functionally similar to wild-type AIRE. Analogously to CBP, p300 localized to AIRE-containing nuclear bodies, however, the overexpression of p300 did not enhance the transcriptional activation of AIRE-regulated genes. Further studies showed that overexpression of p300 stabilized the AIRE protein. Interestingly, gene expression profiling revealed that AIRE, with mutations mimicking K243/K253 acetylation in SAND, was able to activate gene expression, although the affected genes were different and the activation level was lower from those regulated by wild-type AIRE. Our results suggest that the AIRE acetylation can influence the selection of AIRE activated genes. -- Highlights: Black-Right-Pointing-Pointer AIRE is acetylated by the acetyltransferases p300 and CBP. Black-Right-Pointing-Pointer Acetylation occurs between CARD and SAND domains and within the SAND domain. Black-Right-Pointing-Pointer Acetylation increases the size of AIRE nuclear dots. Black-Right-Pointing-Pointer Acetylation increases AIRE protein stability. Black-Right-Pointing-Pointer AIRE acetylation mimic regulates a different set of AIRE

  7. Targeted Quantitation of Acetylated Lysine Peptides by Selected Reaction Monitoring Mass Spectrometry

    Rardin, Matthew J.; Held, Jason M.; Gibson, Bradford W.

    2013-01-01

    Mass spectrometry (MS) allows for the large-scale identification of multiple peptide analytes in complex mixtures. However, the low abundance of acetylated peptides in the overall mixture requires an enrichment step. After enrichment, the resulting acetylated peptides of interest can be quantitated using selected reaction monitoring (SRM)-MS with stable isotope dilution. Here, we describe the enrichment of lysine acetylated peptides from typsin digested mouse liver mitochondria, and the targe...

  8. Production and characterization of a monoclonal antibody to the O-acetylated peptidoglycan of Proteus mirabilis.

    Gyorffy, S; Clarke, A J

    1992-01-01

    A monoclonal antibody (PmPG5-3) specific for the O-acetylated peptidoglycan of Proteus mirabilis 19 was produced by an NS-1 myeloma cell line and purified from ascites fluid by a combination of ammonium sulfate precipitation and affinity chromatography. The monoclonal antibody (an immunoglobulin M) was characterized by a competition enzyme-linked immunosorbent assay to be equally specific for both insoluble and soluble O-acetylated peptidoglycan but weakly recognized chemically de-O-acetylate...

  9. Production of N α -acetylated thymosin α1 in Escherichia coli

    Ren, Yuantao; Yao, Xueqin; Dai, Hongmei; Li, Shulong; Fang, Hongqing; Chen, Huipeng; Zhou, Changlin

    2011-01-01

    Background Thymosin α1 (Tα1), a 28-amino acid N α -acetylated peptide, has a powerful general immunostimulating activity. Although biosynthesis is an attractive means of large-scale manufacture, to date, Tα1 can only be chemosynthesized because of two obstacles to its biosynthesis: the difficulties in expressing small peptides and obtaining N α -acetylation. In this study, we describe a novel production process for N α -acetylated Tα1 in Escherichia coli. Results To obtain recombinant N α -ac...

  10. Efficacy of N-Acetyl Cysteine in Traumatic Brain Injury

    Eakin, Katharine; Baratz-Goldstein, Renana; Pick, Chiam G.; Zindel, Ofra; Balaban, Carey D; Hoffer, Michael E.; Lockwood, Megan; Miller, Jonathan; Hoffer, Barry J.

    2014-01-01

    In this study, using two different injury models in two different species, we found that early post-injury treatment with N-Acetyl Cysteine (NAC) reversed the behavioral deficits associated with the TBI. These data suggest generalization of a protocol similar to our recent clinical trial with NAC in blast-induced mTBI in a battlefield setting [1], to mild concussion from blunt trauma. This study used both weight drop in mice and fluid percussion injury in rats. These were chosen to simulate e...

  11. Aspirin acetylates wild type and mutant p53 in colon cancer cells: identification of aspirin acetylated sites on recombinant p53.

    Ai, Guoqiang; Dachineni, Rakesh; Kumar, D Ramesh; Marimuthu, Srinivasan; Alfonso, Lloyd F; Bhat, G Jayarama

    2016-05-01

    Aspirin's ability to inhibit cell proliferation and induce apoptosis in cancer cell lines is considered to be an important mechanism for its anti-cancer effects. We previously demonstrated that aspirin acetylated the tumor suppressor protein p53 at lysine 382 in MDA-MB-231 human breast cancer cells. Here, we extended these observations to human colon cancer cells, HCT 116 harboring wild type p53, and HT-29 containing mutant p53. We demonstrate that aspirin induced acetylation of p53 in both cell lines in a concentration-dependent manner. Aspirin-acetylated p53 was localized to the nucleus. In both cell lines, aspirin induced p21(CIP1). Aspirin also acetylated recombinant p53 (rp53) in vitro suggesting that it occurs through a non-enzymatic chemical reaction. Mass spectrometry analysis and immunoblotting identified 10 acetylated lysines on rp53, and molecular modeling showed that all lysines targeted by aspirin are surface exposed. Five of these lysines are localized to the DNA-binding domain, four to the nuclear localization signal domain, and one to the C-terminal regulatory domain. Our results suggest that aspirin's anti-cancer effect may involve acetylation and activation of wild type and mutant p53 and induction of target gene expression. This is the first report attempting to characterize p53 acetylation sites targeted by aspirin. PMID:26596838

  12. Preparation of radioactive acetyl-l-carnitine by an enzymatic exchange reaction

    Emaus, R.; Bieber, L.L.

    1982-01-15

    A rapid method for the preparation of (1-/sup 14/C)acetyl-L-carnitine is described. The method involves exchange of (1-/sup 14/C)acetic acid into a pool of unlabeled acetyl-L-carnitine using the enzymes acetyl-CoA synthetase and carnitine acetyltransferase. After isotopic equilibrium is attained, radioactive acetylcarnitine is separated from the other reaction components by chromatography on Dowex 1 (C1/sup -/) anion exchange resin. One of the procedures used to verify the product (1-/sup 14/C)acetyl-L-carnitine can be used to synthesize (3S)-(5-/sup 14/C)citric acid.

  13. Ionizing radiation induces immediate protein acetylation changes in human cardiac microvascular endothelial cells

    Reversible lysine acetylation is a highly regulated post-translational protein modification that is known to regulate several signaling pathways. However, little is known about the radiation-induced changes in the acetylome. In this study, we analyzed the acute post-translational acetylation changes in primary human cardiac microvascular endothelial cells 4 h after a gamma radiation dose of 2 Gy. The acetylated peptides were enriched using anti-acetyl conjugated agarose beads. A total of 54 proteins were found to be altered in their acetylation status, 23 of which were deacetylated and 31 acetylated. Pathway analyses showed three protein categories particularly affected by radiation-induced changes in the acetylation status: the proteins involved in the translation process, the proteins of stress response, and mitochondrial proteins. The activation of the canonical and non-canonical Wnt signaling pathways affecting actin cytoskeleton signaling and cell cycle progression was predicted. The protein expression levels of two nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases, sirtuin 1 and sirtuin 3, were significantly but transiently upregulated 4 but not 24 h after irradiation. The status of the p53 protein, a target of sirtuin 1, was found to be rapidly stabilized by acetylation after radiation exposure. These findings indicate that post-translational modification of proteins by acetylation and deacetylation is essentially affecting the radiation response of the endothelium. (author)

  14. Effect of acetylation on arthropathic activity of group A streptococcal peptidoglycan-polysaccharide fragments.

    Stimpson, S. A.; Lerch, R A; Cleland, D R; Yarnall, D P; Clark, R L; Cromartie, W. J.; Schwab, J. H.

    1987-01-01

    Purified group A streptococcal peptidoglycan-polysaccharide (PG-PS) fragments were either de-O-acylated, or acetylated and then de-O-acylated to yield N-acetylated PG-PS. Native PG-PS was poorly degraded, N-acetylated PG-PS was extensively degraded, and de-O-acylated PG-PS was only slightly degraded by hen egg white lysozyme. N-acetylated PG-PS was also extensively degraded by human lysozyme and partially degraded by rat serum or rat liver extract. After a single intraperitoneal injection of ...

  15. Sirtuin-dependent reversible lysine acetylation of glutamine synthetases reveals an autofeedback loop in nitrogen metabolism.

    You, Di; Yin, Bin-Cheng; Li, Zhi-Hai; Zhou, Ying; Yu, Wen-Bang; Zuo, Peng; Ye, Bang-Ce

    2016-06-14

    In cells of all domains of life, reversible lysine acetylation modulates the function of proteins involved in central cellular processes such as metabolism. In this study, we demonstrate that the nitrogen regulator GlnR of the actinomycete Saccharopolyspora erythraea directly regulates transcription of the acuA gene (SACE_5148), which encodes a Gcn5-type lysine acetyltransferase. We found that AcuA acetylates two glutamine synthetases (GlnA1 and GlnA4) and that this lysine acetylation inactivated GlnA4 (GSII) but had no significant effect on GlnA1 (GSI-β) activity under the conditions tested. Instead, acetylation of GlnA1 led to a gain-of-function that modulated its interaction with the GlnR regulator and enhanced GlnR-DNA binding. It was observed that this regulatory function of acetylated GSI-β enzymes is highly conserved across actinomycetes. In turn, GlnR controls the catalytic and regulatory activities (intracellular acetylation levels) of glutamine synthetases at the transcriptional and posttranslational levels, indicating an autofeedback loop that regulates nitrogen metabolism in response to environmental change. Thus, this GlnR-mediated acetylation pathway provides a signaling cascade that acts from nutrient sensing to acetylation of proteins to feedback regulation. This work presents significant new insights at the molecular level into the mechanisms underlying the regulation of protein acetylation and nitrogen metabolism in actinomycetes. PMID:27247389

  16. p53 targets simian virus 40 large T antigen for acetylation by CBP.

    Poulin, Danielle L; Kung, Andrew L; DeCaprio, James A

    2004-08-01

    Simian virus 40 (SV40) large T antigen (T Ag) interacts with the tumor suppressor p53 and the transcriptional coactivators CBP and p300. Binding of these cellular proteins in a ternary complex has been implicated in T Ag-mediated transformation. It has been suggested that the ability of CBP/p300 to modulate p53 function underlies p53's regulation of cell proliferation and tumorigenesis. In this study, we provide further evidence that CBP activity may be mediated through its synergistic action with p53. We demonstrate that SV40 T Ag is acetylated in vivo in a p53-dependent manner and T Ag acetylation is largely mediated by CBP. The acetylation of T Ag is dependent on its interaction with p53 and on p53's interaction with CBP. We have mapped the site of acetylation on T Ag to the C-terminal lysine residue 697. This acetylation site is conserved between the T antigens of the human polyomaviruses JC and BK, which are also known to interact with p53. We show that both JC and BK T antigens are also acetylated at corresponding sites in vivo. While other proteins are known to be acetylated by CBP/p300, none are known to depend on p53 for acetylation. T Ag acetylation may provide a regulatory mechanism for T Ag binding to a cellular factor or play a role in another aspect of T Ag function. PMID:15254196

  17. Acetylation of cyclin-dependent kinase 5 is mediated by GCN5

    Lee, Juhyung; Yun, Nuri; Kim, Chiho [Department of Systems Biology, Yonsei University College of Life Science and Biotechnology, Seoul 120-749 (Korea, Republic of); Song, Min-Young; Park, Kang-Sik [Department of Physiology and Biomedical Science Institute, Kyung Hee University School of Medicine, Seoul 130-701 (Korea, Republic of); Oh, Young J., E-mail: yjoh@yonsei.ac.kr [Department of Systems Biology, Yonsei University College of Life Science and Biotechnology, Seoul 120-749 (Korea, Republic of)

    2014-04-25

    Highlights: • Cyclin-dependent kinase 5 (CDK5) is present as an acetylated form. • CDK5 is acetylated by GCN5. • CDK5’s acetylation site is mapped at Lys33. • Its acetylation may affect CDK5’s kinase activity. - Abstract: Cyclin-dependent kinase 5 (CDK5), a member of atypical serine/threonine cyclin-dependent kinase family, plays a crucial role in pathophysiology of neurodegenerative disorders. Its kinase activity and substrate specificity are regulated by several independent pathways including binding with its activator, phosphorylation and S-nitrosylation. In the present study, we report that acetylation of CDK5 comprises an additional posttranslational modification within the cells. Among many candidates, we confirmed that its acetylation is enhanced by GCN5, a member of the GCN5-related N-acetyl-transferase family of histone acetyltransferase. Co-immunoprecipitation assay and fluorescent localization study indicated that GCN5 physically interacts with CDK5 and they are co-localized at the specific nuclear foci. Furthermore, liquid chromatography in conjunction with a mass spectrometry indicated that CDK5 is acetylated at Lys33 residue of ATP binding domain. Considering this lysine site is conserved among a wide range of species and other related cyclin-dependent kinases, therefore, we speculate that acetylation may alter the kinase activity of CDK5 via affecting efficacy of ATP coordination.

  18. Preparation of radioactive acetyl-l-carnitine by an enzymatic exchange reaction

    A rapid method for the preparation of [1-14C]acetyl-L-carnitine is described. The method involves exchange of [1-14C]acetic acid into a pool of unlabeled acetyl-L-carnitine using the enzymes acetyl-CoA synthetase and carnitine acetyltransferase. After isotopic equilibrium is attained, radioactive acetylcarnitine is separated from the other reaction components by chromatography on Dowex 1 (C1-) anion exchange resin. One of the procedures used to verify the product [1-14C]acetyl-L-carnitine can be used to synthesize (3S)-[5-14C]citric acid

  19. Synthesis of Andrographolide Glucopyranoside and Selective Cleavage of O-acetyl Groups in Sugar Moiety

    WANG Shao-Min; LIU Hong-Min

    2008-01-01

    Andrographolide glucopyranosides were synthesized from andrographolide and tetra-O-acetyl-β-D-glucopyranosyl bromide via a Koenigs-Knorr reaction and deacetylation with a moderate deacetylation reagent dibutyltin oxide in methanol for the first time.The structures of the andrographolide derivatives were confirmed by IR, NMR,and HRMS.Deprotection of the acetylated andrographolide glucopyranoside with dibutyltin oxide in methanol selectively removed all acetyl groups of the sugar moiety, whereas the acetyl group of the andrographolide part and the base- or acid-sensitive functional groups were retained.

  20. Meat consumption, N-acetyl transferase 1 and 2 polymorphism and risk of breast cancer, in Danish postmenopausal women

    Egeberg, Rikke; Olsen, Anja; Autrup, Herman;

    2008-01-01

    total meat intake and red meat intake and breast cancer risk were confined to intermediate/fast N-acetyl transferase 2 acetylators (P-interaction=0.03 and 0.04). Our findings support an association between meat consumption and breast cancer risk and that N-acetyl transferase 2 polymorphism has a......The aim of this study was to investigate whether polymorphisms in N-acetyl transferase 1 and 2 modify the association between meat consumption and risk of breast cancer. A nested case-control study was conducted among 24697 postmenopausal women included in the 'Diet, Cancer and Health' cohort study...... increment in intake. Compared with slow acetylators, the IRR (95% confidence interval) among fast N-acetyl transferase 1 acetylators was 1.43 (1.03-1.99) and 1.13 (0.83-1.54) among intermediate/fast N-acetyl transferase 2 acetylators. Interaction analyses revealed that the positive associations between...

  1. Comparative analysis of pharmacological treatments with N-acetyl-dl-leucine (Tanganil) and its two isomers (N-acetyl-L-leucine and N-acetyl-D-leucine) on vestibular compensation: Behavioral investigation in the cat.

    Tighilet, Brahim; Leonard, Jacques; Bernard-Demanze, Laurence; Lacour, Michel

    2015-12-15

    Head roll tilt, postural imbalance and spontaneous nystagmus are the main static vestibular deficits observed after an acute unilateral vestibular loss (UVL). In the UVL cat model, these deficits are fully compensated over 6 weeks as the result of central vestibular compensation. N-Acetyl-dl-leucine is a drug prescribed in clinical practice for the symptomatic treatment of acute UVL patients. The present study investigated the effects of N-acetyl-dl-leucine on the behavioral recovery after unilateral vestibular neurectomy (UVN) in the cat, and compared the effects of each of its two isomers N-acetyl-L-leucine and N-acetyl-D-leucine. Efficacy of these three drug treatments has been evaluated with respect to a placebo group (UVN+saline water) on the global sensorimotor activity (observation grids), the posture control (support surface measurement), the locomotor balance (maximum performance at the rotating beam test), and the spontaneous vestibular nystagmus (recorded in the light). Whatever the parameters tested, the behavioral recovery was strongly and significantly accelerated under pharmacological treatments with N-acetyl-dl-leucine and N-acetyl-L-leucine. In contrast, the N-acetyl-D-leucine isomer had no effect at all on the behavioral recovery, and animals of this group showed the same recovery profile as those receiving a placebo. It is concluded that the N-acetyl-L-leucine isomer is the active part of the racemate component since it induces a significant acceleration of the vestibular compensation process similar (and even better) to that observed under treatment with the racemate component only. PMID:26607469

  2. The Metabolic Fate of Deoxynivalenol and Its Acetylated Derivatives in a Wheat Suspension Culture: Identification and Detection of DON-15-O-Glucoside, 15-Acetyl-DON-3-O-Glucoside and 15-Acetyl-DON-3-Sulfate

    Clemens Schmeitzl

    2015-08-01

    Full Text Available Deoxynivalenol (DON is a protein synthesis inhibitor produced by the Fusarium species, which frequently contaminates grains used for human or animal consumption. We treated a wheat suspension culture with DON or one of its acetylated derivatives, 3-acetyl-DON (3-ADON, 15-acetyl-DON (15-ADON and 3,15-diacetyl-DON (3,15-diADON, and monitored the metabolization over a course of 96 h. Supernatant and cell extract samples were analyzed using a tailored LC-MS/MS method for the quantification of DON metabolites. We report the formation of tentatively identified DON-15-O-β-D-glucoside (D15G and of 15-acetyl-DON-3-sulfate (15-ADON3S as novel deoxynivalenol metabolites in wheat. Furthermore, we found that the recently identified 15-acetyl-DON-3-O-β-D-glucoside (15-ADON3G is the major metabolite produced after 15-ADON challenge. 3-ADON treatment led to a higher intracellular content of toxic metabolites after six hours compared to all other treatments. 3-ADON was exclusively metabolized into DON before phase II reactions occurred. In contrast, we found that 15-ADON was directly converted into 15-ADON3G and 15-ADON3S in addition to metabolization into deoxynivalenol-3-O-β-D-glucoside (D3G. This study highlights significant differences in the metabolization of DON and its acetylated derivatives.

  3. The dynamic organization of fungal acetyl-CoA carboxylase

    Hunkeler, Moritz; Stuttfeld, Edward; Hagmann, Anna; Imseng, Stefan; Maier, Timm

    2016-04-01

    Acetyl-CoA carboxylases (ACCs) catalyse the committed step in fatty-acid biosynthesis: the ATP-dependent carboxylation of acetyl-CoA to malonyl-CoA. They are important regulatory hubs for metabolic control and relevant drug targets for the treatment of the metabolic syndrome and cancer. Eukaryotic ACCs are single-chain multienzymes characterized by a large, non-catalytic central domain (CD), whose role in ACC regulation remains poorly characterized. Here we report the crystal structure of the yeast ACC CD, revealing a unique four-domain organization. A regulatory loop, which is phosphorylated at the key functional phosphorylation site of fungal ACC, wedges into a crevice between two domains of CD. Combining the yeast CD structure with intermediate and low-resolution data of larger fragments up to intact ACCs provides a comprehensive characterization of the dynamic fungal ACC architecture. In contrast to related carboxylases, large-scale conformational changes are required for substrate turnover, and are mediated by the CD under phosphorylation control.

  4. Autotrophic acetyl coenzyme A biosynthesis in Methanococcus maripaludis

    To detect autotrophic CO2 assimilation in cell extracts of Methanococcus maripaludis, lactate dehydrogenase and NADH were added to convert pyruvate formed from autotropically synthesized acetyl coenzyme A to lactate. The lactate produced was determined spectrophotometrically. When CO2 fixation was pulled in the direction of lactate synthesis, CO2 reduction to methane was inhibited. Bromoethanesulfonate (BES), a potent inhibitor of methanogenesis, enhanced lactate synthesis, and methyl coenzyme M inhibited it in the absence of BES. Lactate synthesis was dependent on CO2 and H2, but H2 + CO2-independent synthesis was also observed. In cell extracts, the rate of lactate synthesis was about 1.2 nmol min-1 mg of protein-1. When BES was added, the rate of lactate synthesis increased to 2.1 nmol min-1 mg of protein-1. Because acetyl coenzyme A did not stimulate lactate synthesis, pyruvate synthase may have been the limiting activity in these assays. Radiolabel from 14CO2 was incorporated into lactate. The percentages of radiolabel in the C-1, C-2, and C-3 positions of lactate were 73, 33, and 11%, respectively. Both carbon monoxide and formaldehyde stimulated lactate synthesis. 14CH2O was specifically incorporated into the C-3 of lactate, and 14CO was incorporated into the C-1 and C-2 positions. Low concentrations of cyanide also inhibited autotrophic growth, CO dehydrogenase activity, and autotrophic lactate synthesis. These observations are in agreement with the acetogenic pathway of autotrophic CO2 assimilation

  5. A dysregulated acetyl/SUMO switch of FXR promotes hepatic inflammation in obesity.

    Kim, Dong-Hyun; Xiao, Zhen; Kwon, Sanghoon; Sun, Xiaoxiao; Ryerson, Daniel; Tkac, David; Ma, Ping; Wu, Shwu-Yuan; Chiang, Cheng-Ming; Zhou, Edward; Xu, H Eric; Palvimo, Jorma J; Chen, Lin-Feng; Kemper, Byron; Kemper, Jongsook Kim

    2015-01-13

    Acetylation of transcriptional regulators is normally dynamically regulated by nutrient status but is often persistently elevated in nutrient-excessive obesity conditions. We investigated the functional consequences of such aberrantly elevated acetylation of the nuclear receptor FXR as a model. Proteomic studies identified K217 as the FXR acetylation site in diet-induced obese mice. In vivo studies utilizing acetylation-mimic and acetylation-defective K217 mutants and gene expression profiling revealed that FXR acetylation increased proinflammatory gene expression, macrophage infiltration, and liver cytokine and triglyceride levels, impaired insulin signaling, and increased glucose intolerance. Mechanistically, acetylation of FXR blocked its interaction with the SUMO ligase PIASy and inhibited SUMO2 modification at K277, resulting in activation of inflammatory genes. SUMOylation of agonist-activated FXR increased its interaction with NF-κB but blocked that with RXRα, so that SUMO2-modified FXR was selectively recruited to and trans-repressed inflammatory genes without affecting FXR/RXRα target genes. A dysregulated acetyl/SUMO switch of FXR in obesity may serve as a general mechanism for diminished anti-inflammatory response of other transcriptional regulators and provide potential therapeutic and diagnostic targets for obesity-related metabolic disorders. PMID:25425577

  6. Polymorphic acetylation of the antibacterials, sulfamethazine and dapsone, in South Indian subjects.

    Peters, J H; Gordon, G R; Karat, A B

    1975-07-01

    A group of South Indian subjects was studied for their capacities to acetylate sulfamethazine (SMZ) and dapsone (DDS) and to clear DDS from the circulation. An apparent trimodal distribution of acetylator phenotypes was found in 49 subjects (51% slow, 12% intermediate, and 37% rapid acetylators) from measurements of the percentage acetylation of SMZ in 6-hour plasma samples after administration of 10 mg SMZ/kg. The intermediate phenotype was not discernible from either the percentage acetylation of SMZ in urine (collected concurrently with the plasma after SMZ) or that of DDS in plasma after the ingestion of 50 mg DDS by the same subjects. The latter two measurements yielded a bimodal distribution of 59% slow and 41% rapid acetylators, nearly identical to earlier reported distributions of isoniazid inactivator phenotypes in larger numbers of South Indian tuberculosis patients. In the current group, acetylation of DDS and SMZ was positively correlated. The half-time of disappearance (T 1/2) of DDS, an expression of the rate of clearance from the plasma, ranged from 13 to 40 hours. No correlation was found between the subject's capacity to acetylate DDS and the T 1/2 value for DDS. These results were generally consistent with earlier observations made during similar studies of American and Filipino subjects. PMID:1155699

  7. chiral Synthesis of 13-Acetyl-12-hydroxy-podocarpane-8, 11,13-triene-7-one

    2001-01-01

    An enantioselective synthetic route to (+)-13-acetyl-12-hydroxy-podocarpane-8,11,13-triene-7-one 1a and (-)-13-acetyl-12-hydroxy-podocarpane-8,11,13-triene-7-one 1b was developed from (S)-(-)-a -cyclocitral 8a and (R)-(+)-a -cyclocitral 8b.

  8. The Effect of Acetyl-L-Carnitine Administration on Persons with Down Syndrome

    Pueschel, Siegfried M.

    2006-01-01

    Since previous investigations reported improvements in cognition of patients with dementia after acetyl-L-carnitine therapy and since there is an increased risk for persons with Down syndrome to develop Alzheimer disease, this study was designed to investigate the effect of acetyl-L-carnitine administration on neurological, intellectual, and…

  9. Acetylation of Starch with Vinyl Acetate in Imidazolium Ionic Liquids and Characterization of Acetate Distribution

    Starch was acetylated with vinyl acetate in different 1-butyl-3-methylimidazolium (BMIM) salts as solvent in effort to produce starches with different acetylation patterns. Overall degree of substitution was much higher for basic anions such as acetate and dicyanimide (dca) than for neutral anions ...

  10. Effects of acetylation on the emulsifying properties of Artemisia sphaerocephala Krasch. polysaccharide.

    Li, Junjun; Hu, Xinzhong; Li, Xiaoping; Ma, Zhen

    2016-06-25

    In the present study, polysaccharides extracted from Artemisia sphaerocephala Krasch. seeds (ASKP) were acetylated to improve the emulsifying properties of the macromolecules. Several methods were applied for the acetylation purpose, among which the acetic anhydride-pyridine method with formamide as solvent was found to be the most effective one. Acetylated ASKPs with various degree of substitution (DS) were successfully produced and structurally characterized using HPSEC-MALS, FTIR and (1)H NMR techniques in this study. Results showed that acetylation treatment could cause the degradation of ASKP. Moreover, with the increase of DS, both the molecular weight and radius of gyration increased, as well as the molecular conformation trended to be more compact. Low DS (DS: 0.04 and 0.13) conferred acetylated ASKP a lower viscosity than that of ASKP. With the increase of DS, the viscosity of acetylated ASKPs increased and exceeded that of ASKP. Compared with ASKP, acetylated ASKPs could reduce the surface tension to a greater extent and demonstrated a much smaller droplet size (ZD) in an oil/water emulsion system. Acetylated ASKPs were capable of stabilizing the oil/water emulsion for 3 days at 60°C, whose performance was as good as that of gum acacia. In conclusion, such a hydrophobic modification on ASKP conferred it better emulsifying properties. PMID:27083845

  11. Effects of Partially N-acetylated Chitosans to Elicit Resistance Reaction on Brassica napus L.

    ZHANG Xue-kun; TANG Zhang-lin; CHEN Li; GUO Yi-hong; CHEN Yun-ping; LI Jia-na

    2002-01-01

    The effects to elicit resistance reaction on oilseed rape (Brassica napus L. cv Xinongchangjiao )by four partially N-acetylated chitosan 7B, 8B, 9B and 10B (Degree of acetylation (D. A. ) is 30%, 20%,10%, 0%, respectively) and Glycol chitosan (GC, D.A. is 0%) were investigated and compared. Results showed that chitosan were similar to salicylic acid (SA), and could induce resistance reaction, but the reaction was influenced by the degree of acetylation of chitosan. Fully deacetylated chitosans, 10B and GC, elicited chitinase activity, but partially acetylated chitosan, 7B, 8B and 9B, inhibited chitinase activity. Phenyalanine ammonia-lyase (PAL) was also elicited. Elicitor activity increased with on increasing degree of acetylation, 7B induced highest PAL activity among all chitosans. All chitosans induced peroxidase (POD) in a similar level.After elicited by glycol chitosan, like SA treatment, the seedlings increased disease resistance to Sclerotinia sclerotiorum significantly.

  12. Acetylation dynamics of human nuclear proteins during the ionizing radiation-induced DNA damage response

    Bennetzen, Martin; Andersen, J.S.; Lasen, D.H.;

    2013-01-01

    -dependent posttranslational modifications (PT Ms). To complement our previous analysis of IR-induced temporal dynamics of nuclear phosphoproteome, we now identify a range of human nuclear proteins that are dynamically regulated by acetylation, and predominantly deacetylation, during IR-induced DDR by using mass spectrometry......-based proteomic approaches. Apart from cataloging acetylation sites through SILAC proteomic analyses before IR and at 5 and 60 min after IR exposure of U2OS cells, we report that: (1) key components of the transcriptional machinery, such as EP 300 and CREBBP, are dynamically acetylated; (2) that nuclear...... to assess lysine acetylation status and thereby validate the mass spectrometry data. We thus present evidence that nuclear proteins, including those known to regulate cellular functions via epigenetic modifications of histones, are regulated by (de)acetylation in a timely manner upon cell's exposure...

  13. Effect of Acetyl Group on Mechanical Properties of Chitin/Chitosan Nanocrystal: A Molecular Dynamics Study

    Junhe Cui

    2016-01-01

    Full Text Available Chitin fiber is the load-bearing component in natural chitin-based materials. In these materials, chitin is always partially deacetylated to different levels, leading to diverse material properties. In order to understand how the acetyl group enhances the fracture resistance capability of chitin fiber, we constructed atomistic models of chitin with varied acetylation degree and analyzed the hydrogen bonding pattern, fracture, and stress-strain behavior of these models. We notice that the acetyl group can contribute to the formation of hydrogen bonds that can stabilize the crystalline structure. In addition, it is found that the specimen with a higher acetylation degree presents a greater resistance against fracture. This study describes the role of the functional group, acetyl groups, in crystalline chitin. Such information could provide preliminary understanding of nanomaterials when similar functional groups are encountered.

  14. Effect of Acetyl Group on Mechanical Properties of Chitin/Chitosan Nanocrystal: A Molecular Dynamics Study

    Cui, Junhe; Yu, Zechuan; Lau, Denvid

    2016-01-01

    Chitin fiber is the load-bearing component in natural chitin-based materials. In these materials, chitin is always partially deacetylated to different levels, leading to diverse material properties. In order to understand how the acetyl group enhances the fracture resistance capability of chitin fiber, we constructed atomistic models of chitin with varied acetylation degree and analyzed the hydrogen bonding pattern, fracture, and stress-strain behavior of these models. We notice that the acetyl group can contribute to the formation of hydrogen bonds that can stabilize the crystalline structure. In addition, it is found that the specimen with a higher acetylation degree presents a greater resistance against fracture. This study describes the role of the functional group, acetyl groups, in crystalline chitin. Such information could provide preliminary understanding of nanomaterials when similar functional groups are encountered. PMID:26742033

  15. H3K9 acetylation and radial chromatin positioning

    Strašák, Luděk; Bártová, Eva; Harničarová, Andrea; Galiová-Šustáčková, Gabriela; Krejčí, Jana; Kozubek, Stanislav

    2009-01-01

    Roč. 220, č. 1 (2009), s. 91-101. ISSN 0021-9541 R&D Projects: GA MŠk(CZ) LC06027; GA MŠk(CZ) LC535; GA AV ČR(CZ) 1QS500040508; GA AV ČR(CZ) IAA5004306; GA ČR(CZ) GA204/06/0978 Grant ostatní: GA ČR(CZ) GP310/07/P480 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : chromatin structure * RIDGE and anti-RIDGE regions * H3K9 acetylation Subject RIV: BO - Biophysics Impact factor: 4.586, year: 2009

  16. Ach1 is involved in shuttling mitochondrial acetyl units for cytosolic C2 provision in Saccharomyces cerevisiae lacking pyruvate decarboxylase

    Chen, Yun; Zhang, Yiming; Siewers, Verena;

    2015-01-01

    Saccharomyces cerevisiae, acetyl-CoA is compartmentalized in the cytosol, mitochondrion, peroxisome and nucleus, and cannot be directly transported between these compartments. With the acetyl-carnitine or glyoxylate shuttle, acetyl-CoA produced in peroxisomes or the cytoplasm can be transported into the......-fermentative yeast strain. We found that mitochondrial Ach1 can convert acetyl-CoA in this compartment into acetate, which crosses the mitochondrial membrane before being converted into acetyl-CoA in the cytosol. Based on our finding we propose a model in which acetate can be used to exchange acetyl units between...... mitochondria and the cytosol. These results will increase our fundamental understanding of intracellular transport of acetyl units, and also help to develop microbial cell factories for many kinds of acetyl-CoA derived products....

  17. Mechanism of the lysosomal membrane enzyme acetyl coenzyme A: alpha-glucosaminide N-acetyltransferase

    Acetyl-CoA:α-glucosaminide N-acetyltransferase is a lysosomal membrane enzyme, deficient in the genetic disease Sanfilippo C syndrome. The enzyme catalyzes the transfer of an acetyl group from cytoplasmic acetyl-CoA to terminal α-glucosamine residues of heparan sulfate within the organelle. The reaction mechanism was examined using high purified lysosomal membranes from rat liver and human fibroblasts. The N-acetyltransferase reaction is optimal above pH 5.5 and a 2-3 fold stimulation of activity is observed in the presence of 0.1% taurodeoxycholate. Double reciprocal analysis and product inhibition studies indicate that the enzyme works by a Di-Iso Ping Pong Bi Bi mechanism. The binding of acetyl-CoA to the enzyme is measured by exchange label from [3H]CoA to acetyl-CoA, and is optimal at pH's above 7.0. The acetyl-enzyme intermediate is formed by incubating membranes with [3H]acetyl-CoA. The acetyl group can be transferred to glucosamine, forming [3H]N-acetylglucosamine; the transfer is optimal between pH 4 and 5. Lysosomal membranes from Sanfilippo C fibroblasts confirm that these half reactions carried out by the N-acetyltransferase. The enzyme is inactivated by N-bromosuccinimide and diethylpyrocarbonate, indicating that a histidine is involved in the reaction. These results suggest that the histidine residue is at the active site of the enzyme. The properties of the N-acetyltransferase in the membrane, the characterization of the enzyme kinetics, the chemistry of a histidine mediated acetylation and the pH difference across the lysosomal membrane all support a transmembrane acetylation mechanism

  18. Hair Analysis for Determination of Isoniazid Concentrations and Acetylator Phenotype during Antituberculous Treatment

    Michael Eisenhut

    2012-01-01

    Full Text Available Background. Analysis of isoniazid (INH uptake has been based on measurement of plasma concentrations providing a short-term and potentially biased view. Objectives. To establish hair analysis as a tool to measure long-term uptake of INH and to assess whether acetylator phenotype in hair reflects N-acetyltransferase-2 (NAT2 genotype. Design and Methods. INH and acetyl-INH concentrations in hair were determined in patients on INH treatment for M. tuberculosis infection using high pressure liquid chromatography/mass spectrometry. Acetyl-INH/INH ratios were correlated with NAT-2 genotype. Results. Hair concentrations of INH, determined in 40 patients, were not dependent on ethnic group or body mass index and were significantly higher in male compared to female patients (median (range 2.37 ng/mg (0.76–4.9 versus 1.11 ng/mg (0.02–7.20 (P=0.02. Acetyl-INH/INH ratios were a median of 15.2% (14.5 to 31.7 in homozygous rapid acetylator NAT-2 genotype and 37.3% (1.73 to 51.2 in the heterozygous rapid acetylator NAT-2 genotype and both significantly higher than in the slow acetylator NAT-2 genotype with 5.8% (0.53 to 14.4 (P<0.05. Conclusions. Results of hair analysis for INH showed lower concentrations in females. Acetyl-INH/INH ratios were significantly lower in patients with slow acetylator versus rapid acetylator genotypes.

  19. Antioxidant activity of N-acetyl-glucosamine based thiazolidine derivative

    Li Chunlei; Yang Yan; Han Baoqin; Liu Wanshun

    2007-01-01

    N-acetyl-glucosamine,the monomer of chitin,was cyclo-condensed with L-cysteine to prepare thiazolidine derivative:2-N-acetyl-glucosamine-thiazolidine-4(R)-carboxylic acid(GlcNAcCys).The stability of GlcNAcCys was evaluated by high performance liquid chromatography(HPLC)measurement.The results showed that GlcNAcCys Was more stable than other TCA derivatives,especially in alkaline condition.The direct in vitro antioxidative properties of GlcNAcCys were investigated by using UV radiation-induced lipid peroxidation(LPO)in mitochondria and nuclei and.OH-induced LPO in red blood cell (RBC)ghosts models.UV radiation caused dose-dependent LPO in both mitochondria and nuclei,this effect Was catalvzed by addition of Fd2+ while prevented by co-incubation with GlcNAcCys.When nuclei and mitochondria Was treated with 100μl,300μl,500μl of GlcNAcCys and co-incubated at 37℃ for 30min,LPO was decreased to 96%,72%,68%in nuclei and 95%,72%,68% in mitochondria when compared to the UV radiation group respectively.Hydroxyl radicals(.OH)generated by Fenton reaction induced LPO in RBC ghosts.Pretreatment of RBC ghosts with GlcNAcCys could induce antioxidant RBC ghosts and inhibit concentration-dependent malondialdehyde(MDA)formation in antioxidant RBC ghosts.Its inhibition percent Was 14%,35%,36%,42%at 10,20,30,40ms/ml respectively.In a conclusion,the data suggest that GlcNAcCys has antioxidant ability and can significantly inhibit lipid peroxidation in biological samples tested in vitro.

  20. System-wide Studies of N-Lysine Acetylation in Rhodopseudomonas palustris Reveals Substrate Specificity of Protein Acetyltransferases

    Crosby, Heidi A [University of Wisconsin, Madison; Pelletier, Dale A [ORNL; Hurst, Gregory {Greg} B [ORNL; Escalante-Semerena, Jorge C [University of Wisconsin, Madison

    2012-01-01

    Background: Protein acetylation is widespread in prokaryotes. Results: Six new acyl-CoA synthetases whose activities are controlled by acetylation were identified, and their substrate preference established. A new protein acetyltransferase was also identified and its substrate specificity determined. Conclusion: Protein acetyltransferases acetylate a conserved lysine residue in protein substrates. Significance: The R. palustris Pat enzyme specifically acetylates AMP-forming acyl-CoA synthetases and regulates fatty acid metabolism.

  1. Three novel acetylation sites in the Foxp3 transcription factor regulate the suppressive activity of regulatory T cells

    Kwon, Hye-Sook; Lim, Hyung W; Wu, Jessica; Schnoelzer, Martina; Verdin, Eric; Ott, Melanie

    2012-01-01

    The Foxp3 transcription factor is the master regulator of regulatory T cell (Treg) differentiation and function. Its activity is regulated by reversible acetylation. Using mass spectrometry of immunoprecipitated proteins, we identify three novel acetylation sites in murine Foxp3 (K31, K262, and K267) and the corresponding sites in human FoxP3 proteins. Newly raised modification-specific antibodies against acetylated K31 and K267 confirm acetylation of these residues in murine Tregs. Mutant Fo...

  2. 40 CFR 180.1089 - Poly-N-acetyl-D-glucosamine; exemption from the requirement of tolerance.

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Poly-N-acetyl-D-glucosamine; exemption... FOOD Exemptions From Tolerances § 180.1089 Poly-N-acetyl-D-glucosamine; exemption from the requirement... biochemical nematicide poly-N-acetyl-D-glucosamine on a variety of agricultural crops....

  3. A reactivity-selectivity study of the Friedel-Crafts acetylation of 3,3′-dimethylbiphenyl and the oxidation of the acetyl derivatives

    Titinchi Salam JJ

    2012-06-01

    Full Text Available Abstract Background Friedel-Crafts acetylation is an important route to aromatic ketones, in research laboratories and in industry. The acetyl derivatives of 3,3′-dimethylbiphenyl (3,3′-dmbp have applications in the field of liquid crystals and polymers and may be oxidized to the dicarboxylic acids and derivatives that are of interest in cancer treatment. Findings The effect of solvent and temperature on the selectivity of monoacetylation of 3,3’-dmbp by the Perrier addition procedure was studied using stoichiometric amounts of reagents. 4-Ac-3,3′-dmbp was formed almost quantitatively in boiling 1,2-dichloroethane and this is almost twice the yield hitherto reported. Using instead a molar ratio of substrate:AcCl:AlCl3 equal to 1:4:4 or 1:6:6 in boiling 1,2-dichloroethane, acetylation afforded 4,4′- and 4,6′-diacetyl-3,3′-dmbp in a total yield close to 100%. The acetyl derivatives were subsequently converted to the carboxylic acids by hypochlorite oxidation. The relative stabilities of the isomeric products and the corresponding σ-complexes were studied by DFT calculations and the data indicated that mono- and diacetylation followed different mechanisms. Conclusions Friedel-Crafts acetylation of 3,3′-dmbp using the Perrier addition procedure in boiling 1,2-dichloroethane was found to be superior to other recipes. The discrimination against the 6-acetyl derivative during monoacetylation seems to reflect a mechanism including an AcCl:AlCl3 complex or larger agglomerates as the electrophile, whereas the less selective diacetylations of the deactivated 4-Ac-3,3′-dmbp are suggested to include the acetyl cation as the electrophile. The DFT data also showed that complexation of intermediates and products with AlCl3 does not seem to be important in determining the mechanism.

  4. Improved Species-Specific Lysine Acetylation Site Prediction Based on a Large Variety of Features Set.

    Wuyun, Qiqige; Zheng, Wei; Zhang, Yanping; Ruan, Jishou; Hu, Gang

    2016-01-01

    Lysine acetylation is a major post-translational modification. It plays a vital role in numerous essential biological processes, such as gene expression and metabolism, and is related to some human diseases. To fully understand the regulatory mechanism of acetylation, identification of acetylation sites is first and most important. However, experimental identification of protein acetylation sites is often time consuming and expensive. Therefore, the alternative computational methods are necessary. Here, we developed a novel tool, KA-predictor, to predict species-specific lysine acetylation sites based on support vector machine (SVM) classifier. We incorporated different types of features and employed an efficient feature selection on each type to form the final optimal feature set for model learning. And our predictor was highly competitive for the majority of species when compared with other methods. Feature contribution analysis indicated that HSE features, which were firstly introduced for lysine acetylation prediction, significantly improved the predictive performance. Particularly, we constructed a high-accurate structure dataset of H.sapiens from PDB to analyze the structural properties around lysine acetylation sites. Our datasets and a user-friendly local tool of KA-predictor can be freely available at http://sourceforge.net/p/ka-predictor. PMID:27183223

  5. Aberrant histone H4 acetylation in dead somatic cell-cloned calves

    Lei Zhang; Shaohua Wang; Qiang Li; Xiangdong Ding; Yunping Dai; Ning Li

    2008-01-01

    In somatic cell-cloned animals, inefficient epigenetic reprogramming can result in an inappropriate gene expression and histone H4 acetylation is one of the key epigenetic modifications regulating gene expression. In this study, we investigated the levels of histone H4 acetylation of 11 development-related genes and expression levels of 19 genes in lungs of three normal control calves and nine aber-rant somatic cell-cloned calves. The results showed that nine studied genes had decreased acetylation levels in aberrant clones (p 0.05). Whereas 13 genes had significantly decreased expression (p 0.05), and only one gene had higher expression level in clones (p < 0.05). Furthermore, FGFR, GHR, HGFR and IGF1 genes showed lowered levels of both histone H4 acetylation and expression in aberrant clones than in controls, and the level of histone H4 acetylation was even more lowered in aberrant clones than those in controls. It was suggested that the lower levels of histone H4 acetylation in aberrant clones caused by the previous memory of cell differentiation might not support enough chromatin reprogramming, thus affecting appropriate gene expressions, and growth and development of the cloned calves. To our knowledge, this is the first study on how histone H4 acetylation affects gene expression in organs of somatic cell-cloned calves.

  6. Profiling of cytosolic and peroxisomal acetyl-CoA metabolism in Saccharomyces cerevisiae.

    Yun Chen

    Full Text Available As a key intracellular metabolite, acetyl-coenzyme A (acetyl-CoA plays a major role in various metabolic pathways that link anabolism and catabolism. In the yeast Saccharomyces cerevisiae, acetyl-CoA involving metabolism is compartmentalized, and may vary with the nutrient supply of a cell. Membranes separating intracellular compartments are impermeable to acetyl-CoA and no direct transport between the compartments occurs. Thus, without carnitine supply the glyoxylate shunt is the sole possible route for transferring acetyl-CoA from the cytosol or the peroxisomes into the mitochondria. Here, we investigate the physiological profiling of different deletion mutants of ACS1, ACS2, CIT2 and MLS1 individually or in combination under alternative carbon sources, and study how various mutations alter carbon distribution. Based on our results a detailed model of carbon distribution about cytosolic and peroxisomal acetyl-CoA metabolism in yeast is suggested. This will be useful to further develop yeast as a cell factory for the biosynthesis of acetyl-CoA-derived products.

  7. Proteomic Analysis of Lysine Acetylation Sites in Rat Tissues Reveals Organ Specificity and Subcellular Patterns

    Alicia Lundby

    2012-08-01

    Full Text Available Lysine acetylation is a major posttranslational modification involved in a broad array of physiological functions. Here, we provide an organ-wide map of lysine acetylation sites from 16 rat tissues analyzed by high-resolution tandem mass spectrometry. We quantify 15,474 modification sites on 4,541 proteins and provide the data set as a web-based database. We demonstrate that lysine acetylation displays site-specific sequence motifs that diverge between cellular compartments, with a significant fraction of nuclear sites conforming to the consensus motifs G-AcK and AcK-P. Our data set reveals that the subcellular acetylation distribution is tissue-type dependent and that acetylation targets tissue-specific pathways involved in fundamental physiological processes. We compare lysine acetylation patterns for rat as well as human skeletal muscle biopsies and demonstrate its general involvement in muscle contraction. Furthermore, we illustrate that acetylation of fructose-bisphosphate aldolase and glycerol-3-phosphate dehydrogenase serves as a cellular mechanism to switch off enzymatic activity.

  8. Proteomic investigations of lysine acetylation identify diverse substrates of mitochondrial deacetylase sirt3.

    Eri Maria Sol

    Full Text Available Lysine acetylation is a posttranslational modification that is dynamically regulated by the activity of acetyltransferases and deacetylases. The human and mouse genomes encode 18 different lysine deacetylases (KDACs which are key regulators of many cellular processes. Identifying substrates of KDACs and pinpointing the regulated acetylation sites on target proteins may provide important information about the molecular basis of their functions. Here we apply quantitative proteomics to identify endogenous substrates of the mitochondrial deacetylase Sirtuin 3 (Sirt3 by comparing site-specific acetylation in wild-type murine embryonic fibroblasts to Sirt3 knockout cells. We confirm Sirt3-regulated acetylation of several mitochondrial proteins in human cells by comparing acetylation in U2OS cells overexpressing Sirt3 to U2OS cells in which Sirt3 expression was reduced by shRNA. Our data demonstrate that ablation of Sirt3 significantly increases acetylation at dozens of sites on mitochondrial proteins. Substrates of Sirt3 are implicated in various metabolic pathways, including fatty acid metabolism and the tricarboxylic acid cycle. These results imply broader regulatory roles of Sirt3 in the mitochondria by modulating acetylation on diverse substrates. The experimental strategy described here is generic and can be applied to identify endogenous substrates of other lysine deacetylases.

  9. Transport and metabolism of indole-3-acetyl-myo-inositol-galactoside in seedlings of Zea mays

    Komoszynski, M.; Bandurski, R. S.

    1986-01-01

    Indole-3-acetyl-myo-inositol galactoside labeled with 3H in the indole and 14C in the galactose moieties was applied to kernels of 5 day old germinating seedlings of Zea mays. Indole-3-acetyl-myo-inositol galactoside was not transported into either the shoot or root tissue as the intact molecule but was instead hydrolyzed to yield [3H]indole-3-acetyl-myo-inositol and [3H]indole-3-acetic acid which were then transported to the shoot with little radioactivity going to the root. With certain assumption concerning the equilibration of applied [3H]indole-3-acetyl-myo-inositol-[U-14C]galactose with the endogenous pool, it may be concluded that indole-3-acetyl-myo-inositol galactoside in the endosperm supplies about 2 picomoles per plant per hour of indole-3-acetyl-myo-inositol and 1 picomole per plant per hour of indole-3-acetic acid to the shoot and thus is comparable to indole-3-acetyl-myo-inositol as a source of indole-acetic acid for the shoot. Quantitative estimates of the amount of galactose in the kernels suggest that [3H]indole-3-acetyl-myo-inositol-[14C]galactose is hydrolyzed after the compound leaves the endosperm but before it reaches the shoot. In addition, [3H]indole-3-acetyl-myo-inositol-[14C]galactose supplies appreciable amounts of 14C to the shoot and both 14C and 3H to an uncharacterized insoluble fraction of the endosperm.

  10. The small delta antigen of hepatitis delta virus is an acetylated protein and acetylation of lysine 72 may influence its cellular localization and viral RNA synthesis

    Hepatitis delta virus (HDV) is a single-stranded RNA virus that encodes two viral nucleocapsid proteins named small and large form hepatitis delta antigen (S-HDAg and L-HDAg). The S-HDAg is essential for viral RNA replication while the L-HDAg is required for viral assembly. In this study, we demonstrated that HDAg are acetylated proteins. Metabolic labeling with [3H]acetate revealed that both forms of HDAg could be acetylated in vivo. The histone acetyltransferase (HAT) domain of cellular acetyltransferase p300 could acetylate the full-length and the N-terminal 88 amino acids of S-HDAg in vitro. By mass spectrometric analysis of the modified protein, Lys-72 of S-HDAg was identified as one of the acetylation sites. Substitution of Lys-72 to Arg caused the mutant S-HDAg to redistribute from the nucleus to the cytoplasm. The mutant reduced viral RNA accumulation and resulted in the earlier appearance of L-HDAg. These results demonstrated that HDAg is an acetylated protein and mutation of HDAg at Lys-72 modulates HDAg subcellular localization and may participate in viral RNA nucleocytoplasmic shuttling and replication

  11. Genome-wide analysis of H4K5 acetylation associated with fear memory in mice

    Park, C. Sehwan; Rehrauer, Hubert; Mansuy, Isabelle M.

    2013-01-01

    Background Histone acetylation has been implicated in learning and memory in the brain, however, its function at the level of the genome and at individual genetic loci remains poorly investigated. This study examines a key acetylation mark, histone H4 lysine 5 acetylation (H4K5ac), genome-wide and its role in activity-dependent gene transcription in the adult mouse hippocampus following contextual fear conditioning. Results Using ChIP-Seq, we identified 23,235 genes in which H4K5ac correlates...

  12. Genome-wide analysis of H4K5 acetylation associated with fear memory in mice

    Park, C. Sehwan; Rehrauer, Hubert; Mansuy, Isabelle M.

    2013-01-01

    BACKGROUND: Histone acetylation has been implicated in learning and memory in the brain, however, its function at the level of the genome and at individual genetic loci remains poorly investigated. This study examines a key acetylation mark, histone H4 lysine 5 acetylation (H4K5ac), genome-wide and its role in activity-dependent gene transcription in the adult mouse hippocampus following contextual fear conditioning. RESULTS: Using ChIP-Seq, we identified 23,235 genes in which H4K5ac correlat...

  13. Acetylation of GATA-3 affects T-cell survival and homing to secondary lymphoid organs

    Yamagata, Tetsuya; Mitani, Kinuko; Oda, Hideaki; Suzuki, Takahiro; Honda, Hiroaki; Asai, Takashi; Maki, Kazuhiro; Nakamoto, Tetsuya; Hirai, Hisamaru

    2000-01-01

    Acetylation of a transcription factor has recently been shown to play a significant role in gene regulation. Here we show that GATA-3 is acetylated in T cells and that a mutation introduced into amino acids 305–307 (KRR-GATA3) creates local hypoacetylation in GATA-3. Remarkably, KRR-GATA3 possesses the most potent suppressive effect when compared with other mutants that are disrupted in putative acetylation targets. Expressing this mutant in peripheral T cells results in defective T-cell homi...

  14. Proteome-wide mapping of the Drosophila acetylome demonstrates a high degree of conservation of lysine acetylation

    Weinert, Brian T; Wagner, Sebastian A; Horn, Heiko;

    2011-01-01

    . With high-resolution mass spectrometry, we identified 1981 lysine acetylation sites in the proteome of Drosophila melanogaster. We used data sets of experimentally identified acetylation and phosphorylation sites in Drosophila and humans to analyze the evolutionary conservation of these modification...... sites between flies and humans. Site-level conservation analysis revealed that acetylation sites are highly conserved, significantly more so than phosphorylation sites. Furthermore, comparison of lysine conservation in Drosophila and humans with that in nematodes and zebrafish revealed that acetylated...... that acetylation of ubiquitin-conjugating E2 enzymes was evolutionarily conserved, and mutation of a conserved acetylation site impaired the function of the human E2 enzyme UBE2D3. This systems-level analysis of comparative posttranslational modification showed that acetylation is an anciently...

  15. Computational study of the three-dimensional structure of N-acetyltransferase 2-acetyl coenzyme a complex.

    Oda, Akifumi; Kobayashi, Kana; Takahashi, Ohgi

    2010-01-01

    N-Acetyltransferase 2 (NAT2) is one of the most important polymorphic drug-metabolizing enzymes and plays a significant role in individual differences of drug efficacies and/or side effects. Coenzyme A (CoA) is a cofactor in the experimentally determined crystal structure of NAT2, although the acetyl source of acetylation reactions catalyzed by NAT is not CoA, but rather acetyl CoA. In this study, the three-dimensional structure of NAT2, including acetyl CoA, was calculated using molecular dynamics simulation. By substituting acetyl CoA for CoA the amino acid residue Gly286, which is known to transform into a glutamate residue by NAT2*7A and NAT2*7B, comes close to the cofactor binding site. In addition, the binding pocket around the sulfur atom of acetyl CoA expanded in the NAT2-acetyl CoA complex. PMID:20930369

  16. Acetylation Targets the M2 Isoform of Pyruvate Kinase for Degradation through Chaperone-Mediated Autophagy and Promotes Tumor Growth

    Lv, Lei; Li, Dong; Zhao, Di; Lin, Ruiting; Chu, Yajing; Zhang, Heng; Zha, Zhengyu; Liu, Ying; Li, Zi; Xu, Yanping; Wang, Gang; Huang, Yiran; Xiong, Yue; Guan, Kun-Liang; Lei, Qun-Ying

    2016-01-01

    SUMMARY Most tumor cells take up more glucose than normal cells but metabolize glucose via glycolysis even in the presence of normal levels of oxygen, a phenomenon known as the Warburg effect. Tumor cells commonly express the embryonic M2 isoform of pyruvate kinase (PKM2) that may contribute to the metabolism shift from oxidative phosphorylation to aerobic glycolysis and tumorigenesis. Here we show that PKM2 is acetylated on lysine 305 and that this acetylation is stimulated by high glucose concentration. PKM2 K305 acetylation decreases PKM2 enzyme activity and promotes its lysosomal-dependent degradation via chaperone-mediated autophagy (CMA). Acetylation increases PKM2 interaction with HSC70, a chaperone for CMA, and association with lysosomes. Ectopic expression of an acetylation mimetic K305Q mutant accumulates glycolytic intermediates and promotes cell proliferation and tumor growth. These results reveal an acetylation regulation of pyruvate kinase and the link between lysine acetylation and CMA. PMID:21700219

  17. A reactivity-selectivity study of the Friedel-Crafts acetylation of 3,3'-dimethylbiphenyl and the oxidation of the acetyl derivatives

    Titinchi, Salam J.J.; Kamounah, Fadhil S.; Abbo, Hanna S.;

    2012-01-01

    Background: Friedel-Crafts acetylation is an important route to aromatic ketones, in research laboratories and in industry. The acetyl derivatives of 3,3'-dimethylbiphenyl (3,3'-dmbp) have applications in the field of liquid crystals and polymers and may be oxidized to the dicarboxylic acids and...... converted to the carboxylic acids by hypochlorite oxidation. The relative stabilities of the isomeric products and the corresponding s-complexes were studied by DFT calculations and the data indicated that mono-and diacetylation followed different mechanisms. Conclusions: Friedel-Crafts acetylation of 3...... derivatives that are of interest in cancer treatment. Findings: The effect of solvent and temperature on the selectivity of monoacetylation of 3,3'-dmbp by the Perrier addition procedure was studied using stoichiometric amounts of reagents. 4-Ac-3,3'-dmbp was formed almost quantitatively in boiling 1...

  18. Blends of Poly (lactic acid) with Thermoplastic Acetylated Starch

    ZHANG Kun-yu; RAN Xiang-hai; ZHUANG Yu-gang; YAO Bin; DONG Li-song

    2009-01-01

    Blends of poly(lactic acid)(PLA) and thermoplastic acetylated starch(ATPS) were prepared by means of the melt mixing method. The results show that PLA and ATPS were partially miscible, which was confirmed with the measurement of T_g by dynamic mechanical analysis(DMA) and differrential scanning calorimetry(DSC). The mechanical and thermal properties of the blends were improved. With increasing the ATPS content, the elongation at break and impact strength were increased. The elongation at break increased from 5% of neat PLA to 25% of the blend PLA/ATPS40. It was found that the cold crystallization behavior of PLA changed evidently by addition of ATPS. The cold crystallization temperature(T_(cc)) of each of PLA/ATPS blends was found to shift to a lower temperature and the width of exothermic peak became narrow compared with that of neat PLA. The thermogravimetry analy-sis(TGA) results showed that the peak of derivative weight for ATPS moved to higher temperature with increasing PLA content in PLA/ATPS blends. It can be concluded that PLA could increase the thermal stability of ATPS. The rheological measurement reveals the melt elasticity and viscosity of the blends decreased with the increased concentration of ATPS, which was favorable to the processing properties of PLA.

  19. Reference intervals for acetylated fetal hemoglobin in healthy newborns

    Renata Paleari

    2014-09-01

    Full Text Available The acetylated fetal hemoglobin (AcHbF derives from an enzyme-mediated post-translational modification occurring on the N-terminal glycine residues of γ-chains. At present, no established data are available on reference intervals for AcHbF in newborns. A total of 92 healthy infants, with gestational age between 37 and 41 weeks were selected for the establishment of AcHbF reference intervals. Blood samples were collected by heel pricking, when collecting routine neonatal screening, and the hemoglobin pattern was analyzed by high-performance liquid chromatography. AcHbF results were then normalized for HbF content in order to account for differences in hemoglobin switch. No difference was found in AcHbF values between genders (P=0.858. AcHbF results were as follow: 12.8±0.8% (mean±standard deviation, reference interval: 11.3-14.3%. This finding could facilitate further studies aimed to assess the possible use of AcHbF, for instance as a possible fetal metabolic biomarker during pregnancy.

  20. Efficacy of N-acetyl cysteine in traumatic brain injury.

    Eakin, Katharine; Baratz-Goldstein, Renana; Pick, Chiam G; Zindel, Ofra; Balaban, Carey D; Hoffer, Michael E; Lockwood, Megan; Miller, Jonathan; Hoffer, Barry J

    2014-01-01

    In this study, using two different injury models in two different species, we found that early post-injury treatment with N-Acetyl Cysteine (NAC) reversed the behavioral deficits associated with the TBI. These data suggest generalization of a protocol similar to our recent clinical trial with NAC in blast-induced mTBI in a battlefield setting, to mild concussion from blunt trauma. This study used both weight drop in mice and fluid percussion injury in rats. These were chosen to simulate either mild or moderate traumatic brain injury (TBI). For mice, we used novel object recognition and the Y maze. For rats, we used the Morris water maze. NAC was administered beginning 30-60 minutes after injury. Behavioral deficits due to injury in both species were significantly reversed by NAC treatment. We thus conclude NAC produces significant behavioral recovery after injury. Future preclinical studies are needed to define the mechanism of action, perhaps leading to more effective therapies in man. PMID:24740427

  1. Experimental thermochemical study of 3-acetyl-2-methyl-5-phenylthiophene

    Ribeiro da Silva, Manuel A.V., E-mail: risilva@fc.up.p [Centro de Investigacao em Quimica, Department of Chemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal); Santos, Ana Filipa L.O.M. [Centro de Investigacao em Quimica, Department of Chemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal)

    2010-01-15

    The standard (p{sup 0}=0.1MPa) massic energy of combustion, in oxygen, of the crystalline 3-acetyl-2-methyl-5-phenylthiophene was measured, at T = 298.15 K, by rotating-bomb combustion calorimetry, from which the standard molar enthalpy of formation, in the condensed phase, was calculated as DELTA{sub f}H{sub m}{sup 0}(cr)=-(104.3+-3.1)kJ.mol{sup -1}. The corresponding standard molar enthalpy of sublimation, at T = 298.15 K, DELTA{sub cr}{sup g}H{sub m}{sup 0}=(108.9+-0.4)kJ.mol{sup -1}, was derived by the Clausius-Clapeyron equation, from the temperature dependence of the vapour pressures of this compound, measured by the Knudsen effusion mass-loss technique. From the results presented above, the standard molar enthalpy of formation, in the gaseous phase, at T = 298.15 K, was derived, DELTA{sub f}H{sub m}{sup 0}(g)=(4.6+-3.1)kJ.mol{sup -1}. This value, in conjunction with the literature values of the experimental enthalpies of formation of thiophene, 2-methylthiophene, and 3-acetylthiophene, was used to predict the enthalpic increment due to the introduction of a phenyl group in the position 2- of the thiophene ring. The calculated increment was compared with the corresponding ones in benzene and pyridine derivatives.

  2. Efficacy of N-Acetyl Cysteine in Traumatic Brain Injury

    Eakin, Katharine; Baratz-Goldstein, Renana; Pick, Chiam G.; Zindel, Ofra; Balaban, Carey D.; Hoffer, Michael E.; Lockwood, Megan; Miller, Jonathan; Hoffer, Barry J.

    2014-01-01

    In this study, using two different injury models in two different species, we found that early post-injury treatment with N-Acetyl Cysteine (NAC) reversed the behavioral deficits associated with the TBI. These data suggest generalization of a protocol similar to our recent clinical trial with NAC in blast-induced mTBI in a battlefield setting [1], to mild concussion from blunt trauma. This study used both weight drop in mice and fluid percussion injury in rats. These were chosen to simulate either mild or moderate traumatic brain injury (TBI). For mice, we used novel object recognition and the Y maze. For rats, we used the Morris water maze. NAC was administered beginning 30–60 minutes after injury. Behavioral deficits due to injury in both species were significantly reversed by NAC treatment. We thus conclude NAC produces significant behavioral recovery after injury. Future preclinical studies are needed to define the mechanism of action, perhaps leading to more effective therapies in man. PMID:24740427

  3. Efficacy of N-acetyl cysteine in traumatic brain injury.

    Katharine Eakin

    Full Text Available In this study, using two different injury models in two different species, we found that early post-injury treatment with N-Acetyl Cysteine (NAC reversed the behavioral deficits associated with the TBI. These data suggest generalization of a protocol similar to our recent clinical trial with NAC in blast-induced mTBI in a battlefield setting, to mild concussion from blunt trauma. This study used both weight drop in mice and fluid percussion injury in rats. These were chosen to simulate either mild or moderate traumatic brain injury (TBI. For mice, we used novel object recognition and the Y maze. For rats, we used the Morris water maze. NAC was administered beginning 30-60 minutes after injury. Behavioral deficits due to injury in both species were significantly reversed by NAC treatment. We thus conclude NAC produces significant behavioral recovery after injury. Future preclinical studies are needed to define the mechanism of action, perhaps leading to more effective therapies in man.

  4. Carbohydrate-linked asparagine-101 of prothrombin contains a metal ion protected acetylation site. Acetylation of this site causes loss of metal ion induced protein fluorescence change

    Prothrombin fragment 1 (prothrombin residues 1-156) contains two acetylation sites that are protected from derivatization by calcium. The first site was protected by only calcium while the second site was protected by magnesium as well. To identify this second acetylation site, fragment 1 was first acetylated with unlabeled reagent in the presence of magnesium. Metal ions were removed, and the protein was acetylated with radiolabeled reagent. The incorporated radiolabel was stable over long periods of time and at acidic or basic pH as long as elevated temperatures were avoided. The radiolabel was removed by treatment of the protein at pH 10 and 50 0C or with 0.2 M hydroxylamine at 50 0C for at least 30 min. Proteolytic degradation of the protein showed that the radioactivity appeared in a tryptic peptide corresponding to residues 94-111 of prothrombin. Amino acid sequence analysis revealed that the radiolabel was associated with an unextracted sequence product. The major radiolabeled product contained Asn101-Ser102 along with the expected chitobiose attached to Asn-101. NMR analysis revealed the presence of three acetate groups which would correspond to two from the chitobiose plus the incorporated acetate residue. Mass spectral analysis showed the correct mass for this glycopeptide plus a single added acetyl group. Amide 1H NMR analysis showed only three amide protons rather than the anticipated four. On the basis of these several observations, it is postulated that the site of acetylation is the β-amide nitrogen of Asn-101. Consequently, these studies showed an unusual chemical reactivity in prothrombin fragment 1. They further show that metal ion binding to prothrombin fragment 1 and subsequent protein fluorescence quenching involve sites ion the kringle region of the protein

  5. Interactions of acetylated histones with DNA as revealed by UV laser induced histone-DNA crosslinking

    The interaction of acetylated histones with DNA in chromatin has been studied by UV laser-induced crosslinking histones to DNA. After irradiation of the nuclei, the covalently linked protein-DNA complexes were isolated and the presence of histones in them demonstrated immunochemically. When chromatin from irradiated nuclei was treated with clostripain, which selectively cleaved the N-terminal tails of core histones, no one of them was found covalently linked to DNA, thus showing that crosslinking proceeded solely via the N-terminal regions. However, the crosslinking ability of the laser was preserved both upon physiological acetylation of histones, known to be restricted to the N-terminal tails, and with chemically acetylated chromatin. This finding is direct evidence that the postsynthetic histone acetylation does not release the N-terminal tails from interaction with DNA

  6. The percutaneous absorption of 35S-acetyl-L-methionine and L-serine in rabbit

    The authors had reported that L-cysteine probably was formed from acetyl-L-methionine and L-serine through cystathionine pathway by the skin enzyme of rabbit, and the solution composed of acetyl-L-methionine and L-serine exhibited the effectiveness to the hair growth in rabbit. This report shows that, by the application of 35S-acetyl-L-methionine and L-serine to the skin of rabbit and in vitro analysis of the metabolites of 35S-compounds, 35S-acetyl-L-methionine was absorbed into the hair tissues for many hours, and half 35S-L-cystine was formed in vitro and in vivo. When total amount of 35S in the hair was measured, the radiochemical activities were clearly shown as almost 35S-L-cystine. (auth.)

  7. Acetylation regulates monopolar attachment at multiple levels during meiosis I in fission yeast

    Kagami, Ayano; Sakuno, Takeshi; Yamagishi, Yuya; Ishiguro, Tadashi; Tsukahara, Tatsuya; Shirahige, Katsuhiko; Tanaka, Koichi; Watanabe, Yoshinori

    2011-01-01

    This study shows that multiple acetylations are crucial for establishing and maintaining core centromere cohesion in meiosis. Eso1 establishes it during S phase, whereas Moa1 maintains cohesion after S phase.

  8. Physiology: Kinetics of Acetyl Coenzyme A: Arylamine N-Acetyltransferase from Human Cumulus Cells

    Chang, Chi-Chen; Hsieh, Yao-Yuan; CHUNG, JING-GUNG; Tsai, Horng-Der; Tsai, Chang-Hai

    2001-01-01

    Purpose:N-acetyltransferase (NAT) activity is involved in the detoxification of exogenous amines. We aimed to evaluate the kinetics of acetyl coenzyme A (AcCoA): arylamine NAT for human cumulus cells.

  9. The Synthesis of Some Novel N-[a-(Isoflavone-7-O-)Acetyl ] Amino Acid Derivatives

    2000-01-01

    A series of novel N-[(α)-(isoflavone-7-O-)acetyl] amino acid methyl esters were prepared from the efficient and regioselective alkylation of isoflavones with chloroacetyl amino acid derivatives under mild condition.

  10. Preparation and structural characterization of O-acetyl agarose with low degree of substitution

    Rosangela B. Garcia

    2000-09-01

    Full Text Available Among the biodegradable polymers, the polysaccharides have been found to be promising carriers for bioactive molecules. From a general standpoint, they present several reactive groups, such as hydroxyl, carboxyl and amine, that can be modified in a number of ways, giving rise to suitable devices for controlled release. In this paper, agarose was submitted to O-acetylation reactions under heterogeneous conditions, using acetic anhydride and pyridine, aiming to observe the effect of acetyl groups on the agarose properties. The products were characterized by Infrared and ¹H NMR spectroscopies. In the range of average acetylation degrees (DA 0.07-0.48, the polymers presented partial solubility in boiling water and in common organic solvents. The ¹H NMR spectra presented evidences of non-homogeneous acetyl group distribution along the chains, as concluded from the solubility of only one of the fractions with DA<0.09, in boiling water .

  11. Density Functional Theory Study on the Histidine-assisted Mechanism of Arylamine N-Acetyltransferase Acetylation

    QIAO Qing-An; GAO Shan-Min; JIN Yue-Qing; CHEN Xin; SUN Xiao-Min; YANG Chuan-Lu

    2008-01-01

    Arylamine N-acetyltransferases (NATs, EC 2.3.1.5) catalyze the N-acetylation of primary arylamines, and play a key role in the biotransformation and metabolism of drugs, carcinogens, etc.In this paper, three possible reaction mechanisms are investigated and the results indicate that if the acetyl group directly transfers from the donor to the acceptor, the high activation energies will make it hard to obtain the target products.When using histidine to mediate the acetylation process, these energies will drop in the 15~45 kJ/mol range.If the histidine residue is protonated, the corresponding energies will be decreased by about 35~87 kJ/mol.The calculations predict an enzymatic acetylation mechanism that undergoes a thiolate-imidazolium pair, which agrees with the experimental results very well.

  12. Data for global lysine-acetylation analysis in rice (Oryza sativa).

    Xiong, Yehui; Zhang, Kai; Cheng, Zhongyi; Wang, Guo-Liang; Liu, Wende

    2016-06-01

    Rice is one of the most important crops for human consumption and is a staple food for over half of the world׳s population (Yu et al., 2002) [1]. A systematic identification of the lysine acetylome was performed by our research (Xiong et al., 2016) [2]. Rice plant samples were collected from 5 weeks old seedlings (Oryza sativa, Nipponbare). After the trypsin digestion and immunoaffinity precipitation, LC-MS/MS approach was used to identify acetylated peptides. After the collected MS/MS data procession and GO annotation, the InterProScan was used to annotate protein domain. Subcellular localization of the identified acetylated proteins was predicted by WoLF PSORT. The KEGG pathway database was used to annotate identified acetylated protein interactions, reactions, and relations. The data, supplied in this article, are related to "A comprehensive catalog of the lysine-acetylation targets in rice (O. sativa) based on proteomic analyses" by Xiong et al. (2016) [2]. PMID:26977447

  13. A reactivity-selectivity study of the Friedel-Crafts acetylation of 3,3′-dimethylbiphenyl and the oxidation of the acetyl derivatives

    Titinchi Salam JJ; Kamounah Fadhil S; Abbo Hanna S; Hammerich Ole

    2012-01-01

    Abstract Background Friedel-Crafts acetylation is an important route to aromatic ketones, in research laboratories and in industry. The acetyl derivatives of 3,3′-dimethylbiphenyl (3,3′-dmbp) have applications in the field of liquid crystals and polymers and may be oxidized to the dicarboxylic acids and derivatives that are of interest in cancer treatment. Findings The effect of solvent and temperature on the selectivity of monoacetylation of 3,3’-dmbp by the Perrier addition procedure was st...

  14. Ku70 acetylation mediates neuroblastoma cell death induced by histone deacetylase inhibitors

    Subramanian, Chitra; Opipari, Anthony W.; Bian, Xin; Castle, Valerie P; Kwok, Roland P S

    2005-01-01

    Histone deacetylase inhibitors (HDACIs) are therapeutic drugs that inhibit deacetylase activity, thereby increasing acetylation of many proteins, including histones. HDACIs have antineoplastic effects in preclinical and clinical trials and are being considered for cancers with unmet therapeutic need, including neuroblastoma (NB). Uncertainty of how HDACI-induced protein acetylation leads to cell death, however, makes it difficult to determine which tumors are likely to be responsive to these ...

  15. Tip60-mediated acetylation activates transcription independent apoptotic activity of Abl

    Pandita Tej K

    2011-07-01

    Full Text Available Abstract Background The proto-oncogene, c-Abl encodes a ubiquitously expressed tyrosine kinase that critically governs the cell death response induced by genotoxic agents such as ionizing radiation and cisplatin. The catalytic function of Abl, which is essential for executing DNA damage response (DDR, is normally tightly regulated but upregulated several folds upon IR exposure due to ATM-mediated phosphorylation on S465. However, the mechanism/s leading to activation of Abl's apoptotic activity is currently unknown. Results We investigated the role of acetyl modification in regulating apoptotic activity of Abl and the results showed that DNA strand break-inducing agents, ionizing radiation and bleomycin induced Abl acetylation. Using mass spectrophotometry and site-specific acetyl antibody, we identified Abl K921, located in the DNA binding domain, and conforming to one of the lysine residue in the consensus acetylation motif (KXXK--X3-5--SGS is acetylated following DNA damage. We further observed that the S465 phosphorylated Abl is acetyl modified during DNA damage. Signifying the modification, cells expressing the non acetylatable K921R mutant displayed attenuated apoptosis compared to wild-type in response to IR or bleomycin treatment. WT-Abl induced apoptosis irrespective of new protein synthesis. Furthermore, upon γ-irradiation K921R-Abl displayed reduced chromatin binding compared to wild type. Finally, loss of Abl K921 acetylation in Tip60-knocked down cells and co-precipitation of Abl with Tip60 in DNA damaged cells identified Tip60 as an Abl acetylase. Conclusion Collective data showed that DNA damage-induced K921 Abl acetylation, mediated by Tip60, stimulates transcriptional-independent apoptotic activity and chromatin-associative property thereby defining a new regulatory mechanism governing Abl's DDR function.

  16. Physical and Functional HAT/HDAC Interplay Regulates Protein Acetylation Balance

    Alessia Peserico; Cristiano Simone

    2011-01-01

    The balance between protein acetylation and deacetylation controls several physiological and pathological cellular processes, and the enzymes involved in the maintenance of this equilibrium—acetyltransferases (HATs) and deacetylases (HDACs)—have been widely studied. Presently, the evidences obtained in this field suggest that the dynamic acetylation equilibrium is mostly maintained through the physical and functional interplay between HAT and HDAC activities. This model overcomes the classica...

  17. Identification and characterization of genes involved in Arabidopsis thaliana cell wall acetylation

    de Souza, Amancio Jose

    2014-01-01

    Most non-cellulosic plant cell wall polysaccharides including the hemicellulose xyloglucan and the pectic polysaccharides can be O-acetylated. This feature has direct significance in the use of these polymers in the food and biofuel industry. For example, increased pectin acetylation can reduce its gelling abilities and is hence detrimental in its application as a food thickener or emulsifier. In general, plant biomass with wall polymers with high acetate content can negatively influence biom...

  18. Acetyl salicylic acid augments functional recovery following sciatic nerve crush in mice

    Gunale Bhagawat K; Prasanna C G; Subbanna Prasanna; Tyagi Manoj G

    2007-01-01

    Abstract Cyclin-dependent kinase 5 (CDK-5) appears to play a significant role in peripheral nerve regeneration as CDK-5 inhibition retards nerve regeneration following nerve crush. Anti-inflammatory drug acetyl salicylic acid elevates CDK-5 and reduces ischemia – reperfusion injury in cultured neurons. In this study we have evaluated the effect of acetyl salicylic acid on functional recovery following sciatic nerve crush in mice. Eighteen Swiss albino mice underwent unilateral sciatic nerve c...

  19. Mapping dynamic histone acetylation patterns to gene expression in nanog-depleted murine embryonic stem cells.

    Markowetz, Florian; Mulder, Klaas W; Airoldi, Edoardo M; Lemischka, Ihor R; Troyanskaya, Olga G

    2010-01-01

    Embryonic stem cells (ESC) have the potential to self-renew indefinitely and to differentiate into any of the three germ layers. The molecular mechanisms for self-renewal, maintenance of pluripotency and lineage specification are poorly understood, but recent results point to a key role for epigenetic mechanisms. In this study, we focus on quantifying the impact of histone 3 acetylation (H3K9,14ac) on gene expression in murine embryonic stem cells. We analyze genome-wide histone acetylation patterns and gene expression profiles measured over the first five days of cell differentiation triggered by silencing Nanog, a key transcription factor in ESC regulation. We explore the temporal and spatial dynamics of histone acetylation data and its correlation with gene expression using supervised and unsupervised statistical models. On a genome-wide scale, changes in acetylation are significantly correlated to changes in mRNA expression and, surprisingly, this coherence increases over time. We quantify the predictive power of histone acetylation for gene expression changes in a balanced cross-validation procedure. In an in-depth study we focus on genes central to the regulatory network of Mouse ESC, including those identified in a recent genome-wide RNAi screen and in the PluriNet, a computationally derived stem cell signature. We find that compared to the rest of the genome, ESC-specific genes show significantly more acetylation signal and a much stronger decrease in acetylation over time, which is often not reflected in a concordant expression change. These results shed light on the complexity of the relationship between histone acetylation and gene expression and are a step forward to dissect the multilayer regulatory mechanisms that determine stem cell fate. PMID:21187909

  20. In vitro phosphorylation and acetylation of the murine pocket protein Rb2/p130.

    Muhammad Saeed

    Full Text Available The retinoblastoma protein (pRb and the related proteins Rb2/p130 and 107 represent the "pocket protein" family of cell cycle regulators. A key function of these proteins is the cell cycle dependent modulation of E2F-regulated genes. The biological activity of these proteins is controlled by acetylation and phosphorylation in a cell cycle dependent manner. In this study we attempted to investigate the interdependence of acetylation and phosphorylation of Rb2/p130 in vitro. After having identified the acetyltransferase p300 among several acetyltransferases to be associated with Rb2/p130 during S-phase in NIH3T3 cells in vivo, we used this enzyme and the CDK4 protein kinase for in vitro modification of a variety of full length Rb2/p130 and truncated versions with mutations in the acetylatable lysine residues 1079, 128 and 130. Mutation of these residues results in the complete loss of Rb2/p130 acetylation. Replacement of lysines by arginines strongly inhibits phosphorylation of Rb2/p130 by CDK4; the inhibitory effect of replacement by glutamines is less pronounced. Preacetylation of Rb2/p130 strongly enhances CDK4-catalyzed phosphorylation, whereas deacetylation completely abolishes in vitro phosphorylation. In contrast, phosphorylation completely inhibits acetylation of Rb2/p130 by p300. These results suggest a mutual interdependence of modifications in a way that acetylation primes Rb2/p130 for phosphorylation and only dephosphorylated Rb2/p130 can be subject to acetylation. Human papillomavirus 16-E7 protein, which increases acetylation of Rb2/p130 by p300 strongly reduces phosphorylation of this protein by CDK4. This suggests that the balance between phosphorylation and acetylation of Rb2/p130 is essential for its biological function in cell cycle control.

  1. Hair Analysis for Determination of Isoniazid Concentrations and Acetylator Phenotype during Antituberculous Treatment

    Michael Eisenhut; Detlef Thieme; Dagmar Schmid; Sybille Fieseler; Hans Sachs

    2012-01-01

    Background. Analysis of isoniazid (INH) uptake has been based on measurement of plasma concentrations providing a short-term and potentially biased view. Objectives. To establish hair analysis as a tool to measure long-term uptake of INH and to assess whether acetylator phenotype in hair reflects N-acetyltransferase-2 (NAT2) genotype. Design and Methods. INH and acetyl-INH concentrations in hair were determined in patients on INH treatment for M. tuberculosis infection using high pressure liq...

  2. Micronutrients, N-acetyl cysteine, probiotics and prebiotics, a review of effectiveness in reducing HIV progression

    Hummelen, Ruben; Hemsworth, Jaimie; Reid, Gregor

    2010-01-01

    textabstractLow serum concentrations of micronutrients, intestinal abnormalities, and an inflammatory state have been associated with HIV progression. These may be ameliorated by micronutrients, N-acetyl cysteine, probiotics, and prebiotics. This review aims to integrate the evidence from clinical trials of these interventions on the progression of HIV. Vitamin B, C, E, and folic acid have been shown to delay the progression of HIV. Supplementation with selenium, N-acetyl cysteine, probiotics...

  3. Micronutrients, N-Acetyl Cysteine, Probiotics and Prebiotics, a Review of Effectiveness in Reducing HIV Progression

    Ruben Hummelen; Jaimie Hemsworth; Gregor Reid

    2010-01-01

    Low serum concentrations of micronutrients, intestinal abnormalities, and an inflammatory state have been associated with HIV progression. These may be ameliorated by micronutrients, N-acetyl cysteine, probiotics, and prebiotics. This review aims to integrate the evidence from clinical trials of these interventions on the progression of HIV. Vitamin B, C, E, and folic acid have been shown to delay the progression of HIV. Supplementation with selenium, N-acetyl cysteine, probiotics, and prebio...

  4. Micronutrients, N-Acetyl Cysteine, Probiotics and Prebiotics, A Review of Effectiveness in Reducing HIV Progression

    Hummelen, Ruben; Hemsworth, Jaimie; Reid, Gregor

    2010-01-01

    textabstractLow serum concentrations of micronutrients, intestinal abnormalities, and an inflammatory state have been associated with HIV progression. These may be ameliorated by micronutrients, N-acetyl cysteine, probiotics, and prebiotics. This review aims to integrate the evidence from clinical trials of these interventions on the progression of HIV. Vitamin B, C, E, and folic acid have been shown to delay the progression of HIV. Supplementation with selenium, N-acetyl cysteine, probiotics...

  5. Targeted amino-terminal acetylation of recombinant proteins in E. coli.

    Matthew Johnson

    Full Text Available One major limitation in the expression of eukaryotic proteins in bacteria is an inability to post-translationally modify the expressed protein. Amino-terminal acetylation is one such modification that can be essential for protein function. By co-expressing the fission yeast NatB complex with the target protein in E.coli, we report a simple and widely applicable method for the expression and purification of functional N-terminally acetylated eukaryotic proteins.

  6. Hippocampal histone acetylation regulates object recognition and the estradiol-induced enhancement of object recognition

    Zhao, Zaorui; Fan, Lu; Fortress, Ashley M.; Boulware, Marissa I.; Frick, Karyn M.

    2012-01-01

    Histone acetylation has recently been implicated in learning and memory processes, yet necessity of histone acetylation for such processes has not been demonstrated using pharmacological inhibitors of histone acetyltransferases (HATs). As such, the present study tested whether garcinol, a potent HAT inhibitor in vitro, could impair hippocampal memory consolidation and block the memory-enhancing effects of the modulatory hormone 17β-estradiol (E2). We first showed that bilateral infusion of ga...

  7. AMPK/Snf1 signaling regulates histone acetylation: Impact on gene expression and epigenetic functions.

    Salminen, Antero; Kauppinen, Anu; Kaarniranta, Kai

    2016-08-01

    AMP-activated protein kinase (AMPK) and its yeast homolog, Snf1, are critical regulators in the maintenance of energy metabolic balance not only stimulating energy production but also inhibiting energy-consuming processes. The AMPK/Snf1 signaling controls energy metabolism by specific phosphorylation of many metabolic enzymes and transcription factors, enhancing or suppressing their functions. The AMPK/Snf1 complexes can be translocated from cytoplasm into nuclei where they are involved in the regulation of transcription. Recent studies have indicated that AMPK/Snf1 activation can control histone acetylation through different mechanisms affecting not only gene transcription but also many other epigenetic functions. For instance, AMPK/Snf1 enzymes can phosphorylate the histone H3S10 (yeast) and H2BS36 (mammalian) sites which activate specific histone acetyltransferases (HAT), consequently enhancing histone acetylation. Moreover, nuclear AMPK can phosphorylate type 2A histone deacetylases (HDAC), e.g. HDAC4 and HDAC5, triggering their export from nuclei thus promoting histone acetylation reactions. AMPK activation can also increase the level of acetyl CoA, e.g. by inhibiting fatty acid and cholesterol syntheses. Acetyl CoA is a substrate for HATs, thus increasing their capacity for histone acetylation. On the other hand, AMPK can stimulate the activity of nicotinamide phosphoribosyltransferase (NAMPT) which increases the level of NAD(+). NAD(+) is a substrate for nuclear sirtuins, especially for SIRT1 and SIRT6, which deacetylate histones and transcription factors, e.g. those regulating ribosome synthesis and circadian clocks. Histone acetylation is an important epigenetic modification which subsequently can affect chromatin remodeling, e.g. via bromodomain proteins. We will review the signaling mechanisms of AMPK/Snf1 in the control of histone acetylation and subsequently clarify their role in the epigenetic regulation of ribosome synthesis and circadian clocks

  8. Novel myelin penta- and hexa-acetyl-galactosyl-ceramides: structural characterization and immunoreactivity in cerebrospinal fluid

    Podbielska, Maria; Dasgupta, Somsankar; Levery, Steven B;

    2010-01-01

    Fast migrating cerebrosides (FMC) are derivatives of galactosylceramide (GalCer). The structures of the most hydrophobic FMC-5, FMC-6, and FMC-7 were determined by electrospray ionization linear ion-trap mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy complementing previous......GL-II from Mycoplasma fermentans. The cross-reactivity of highly acetylated GalCer with microbial acyl-glycolipid raises the possibility that myelin-O-acetyl-cerebrosides, bacterial infection, and neurological disease are linked....

  9. Synthesis of O-[11C]acetyl CoA, O-[11C]acetyl-L-carnitine, and L-[11C]carnitine labelled in specific positions, applied in PET studies on rhesus monkey

    The syntheses of L-carnitine, O-acetyl CoA, and O-acetyl-L-carnitine labelled with 11C at the 1- or 2-position of the acetyl group or the N-methyl position of carnitine, using the enzymes acetyl CoA synthetase and carnitine acetyltransferase, are described. With a total synthesis time of 45 min, O-[1-11C]acetyl CoA and O-[2-11C]acetyl CoA was obtained in 60-70% decay-corrected radiochemical yield, and O-[1-11C]acetyl-L-carnitine and O-[2-11C]acetyl-L-carnitine in 70-80% yield, based on [1-11C]acetate or [2-11C]acetate, respectively. By an N-methylation reaction with [11C]methyl iodide, L-[methyl-11C]carnitine was obtained within 30 min, and O-acetyl-L-[methyl-11C]carnitine within 40 min, giving a decay-corrected radiochemical yield of 60% and 40-50%, respectively, based on [11C]methyl iodide. Initial data of the kinetics of the different 11C-labelled L-carnitine and acetyl-L-carnitines in renal cortex of anaesthetized monkey (Macaca mulatta) are presented

  10. Synthesis of O-[{sup 11}C]acetyl CoA, O-[{sup 11}C]acetyl-L-carnitine, and L-[{sup 11}C]carnitine labelled in specific positions, applied in PET studies on rhesus monkey

    Jacobson, Gunilla B.; Watanabe, Yasuyoshi; Valind, Sven; Kuratsune, Hirohiko; Laangstroem, Bengt

    1997-07-01

    The syntheses of L-carnitine, O-acetyl CoA, and O-acetyl-L-carnitine labelled with {sup 11}C at the 1- or 2-position of the acetyl group or the N-methyl position of carnitine, using the enzymes acetyl CoA synthetase and carnitine acetyltransferase, are described. With a total synthesis time of 45 min, O-[1-{sup 11}C]acetyl CoA and O-[2-{sup 11}C]acetyl CoA was obtained in 60-70% decay-corrected radiochemical yield, and O-[1-{sup 11}C]acetyl-L-carnitine and O-[2-{sup 11}C]acetyl-L-carnitine in 70-80% yield, based on [1-{sup 11}C]acetate or [2-{sup 11}C]acetate, respectively. By an N-methylation reaction with [{sup 11}C]methyl iodide, L-[methyl-{sup 11}C]carnitine was obtained within 30 min, and O-acetyl-L-[methyl-{sup 11}C]carnitine within 40 min, giving a decay-corrected radiochemical yield of 60% and 40-50%, respectively, based on [{sup 11}C]methyl iodide. Initial data of the kinetics of the different {sup 11}C-labelled L-carnitine and acetyl-L-carnitines in renal cortex of anaesthetized monkey (Macaca mulatta) are presented.

  11. Application of the MIDAS approach for analysis of lysine acetylation sites.

    Evans, Caroline A; Griffiths, John R; Unwin, Richard D; Whetton, Anthony D; Corfe, Bernard M

    2013-01-01

    Multiple Reaction Monitoring Initiated Detection and Sequencing (MIDAS™) is a mass spectrometry-based technique for the detection and characterization of specific post-translational modifications (Unwin et al. 4:1134-1144, 2005), for example acetylated lysine residues (Griffiths et al. 18:1423-1428, 2007). The MIDAS™ technique has application for discovery and analysis of acetylation sites. It is a hypothesis-driven approach that requires a priori knowledge of the primary sequence of the target protein and a proteolytic digest of this protein. MIDAS essentially performs a targeted search for the presence of modified, for example acetylated, peptides. The detection is based on the combination of the predicted molecular weight (measured as mass-charge ratio) of the acetylated proteolytic peptide and a diagnostic fragment (product ion of m/z 126.1), which is generated by specific fragmentation of acetylated peptides during collision induced dissociation performed in tandem mass spectrometry (MS) analysis. Sequence information is subsequently obtained which enables acetylation site assignment. The technique of MIDAS was later trademarked by ABSciex for targeted protein analysis where an MRM scan is combined with full MS/MS product ion scan to enable sequence confirmation. PMID:23381851

  12. Dichotomy in the Epigenetic Mark Lysine Acetylation is Critical for the Proliferation of Prostate Cancer Cells

    Pathak, Ravi [Department of Structural and Chemical Biology, Mount Sinai School of Medicine, 1425 Madison Ave, New York, NY 10029 (United States); Philizaire, Marc [Medgar Evers College, City University of New York, 1638 Bedford Ave, 403D, Brooklyn, NY 11225 (United States); Mujtaba, Shiraz, E-mail: smujtaba@mec.cuny.edu [Department of Structural and Chemical Biology, Mount Sinai School of Medicine, 1425 Madison Ave, New York, NY 10029 (United States); Medgar Evers College, City University of New York, 1638 Bedford Ave, 403D, Brooklyn, NY 11225 (United States)

    2015-08-19

    The dynamics of lysine acetylation serve as a major epigenetic mark, which regulates cellular response to inflammation, DNA damage and hormonal changes. Microarray assays reveal changes in gene expression, but cannot predict regulation of a protein function by epigenetic modifications. The present study employs computational tools to inclusively analyze microarray data to understand the potential role of acetylation during development of androgen-independent PCa. The data revealed that the androgen receptor interacts with 333 proteins, out of which at least 92 proteins were acetylated. Notably, the number of cellular proteins undergoing acetylation in the androgen-dependent PCa was more as compared to the androgen-independent PCa. Specifically, the 32 lysine-acetylated proteins in the cellular models of androgen-dependent PCa were mainly involved in regulating stability as well as pre- and post-processing of mRNA. Collectively, the data demonstrate that protein lysine acetylation plays a crucial role during the transition of androgen-dependent to -independent PCa, which importantly, could also serve as a functional axis to unravel new therapeutic targets.

  13. Histone acetylation and CREB binding protein are required for neuronal resistance against ischemic injury.

    Ferah Yildirim

    Full Text Available Epigenetic transcriptional regulation by histone acetylation depends on the balance between histone acetyltransferase (HAT and deacetylase activities (HDAC. Inhibition of HDAC activity provides neuroprotection, indicating that the outcome of cerebral ischemia depends crucially on the acetylation status of histones. In the present study, we characterized the changes in histone acetylation levels in ischemia models of focal cerebral ischemia and identified cAMP-response element binding protein (CREB-binding protein (CBP as a crucial factor in the susceptibility of neurons to ischemic stress. Both neuron-specific RNA interference and neurons derived from CBP heterozygous knockout mice showed increased damage after oxygen-glucose deprivation (OGD in vitro. Furthermore, we demonstrated that ischemic preconditioning by a short (5 min subthreshold occlusion of the middle cerebral artery (MCA, followed 24 h afterwards by a 30 min occlusion of the MCA, increased histone acetylation levels in vivo. Ischemic preconditioning enhanced CBP recruitment and histone acetylation at the promoter of the neuroprotective gene gelsolin leading to increased gelsolin expression in neurons. Inhibition of CBP's HAT activity attenuated neuronal ischemic preconditioning. Taken together, our findings suggest that the levels of CBP and histone acetylation determine stroke outcome and are crucially associated with the induction of an ischemia-resistant state in neurons.

  14. Dichotomy in the Epigenetic Mark Lysine Acetylation is Critical for the Proliferation of Prostate Cancer Cells

    The dynamics of lysine acetylation serve as a major epigenetic mark, which regulates cellular response to inflammation, DNA damage and hormonal changes. Microarray assays reveal changes in gene expression, but cannot predict regulation of a protein function by epigenetic modifications. The present study employs computational tools to inclusively analyze microarray data to understand the potential role of acetylation during development of androgen-independent PCa. The data revealed that the androgen receptor interacts with 333 proteins, out of which at least 92 proteins were acetylated. Notably, the number of cellular proteins undergoing acetylation in the androgen-dependent PCa was more as compared to the androgen-independent PCa. Specifically, the 32 lysine-acetylated proteins in the cellular models of androgen-dependent PCa were mainly involved in regulating stability as well as pre- and post-processing of mRNA. Collectively, the data demonstrate that protein lysine acetylation plays a crucial role during the transition of androgen-dependent to -independent PCa, which importantly, could also serve as a functional axis to unravel new therapeutic targets

  15. Intrinsic Tau Acetylation Is Coupled to Auto-Proteolytic Tau Fragmentation.

    Todd J Cohen

    Full Text Available Tau proteins are abnormally aggregated in a range of neurodegenerative tauopathies including Alzheimer's disease (AD. Recently, tau has emerged as an extensively post-translationally modified protein, among which lysine acetylation is critical for normal tau function and its pathological aggregation. Here, we demonstrate that tau isoforms have different propensities to undergo lysine acetylation, with auto-acetylation occurring more prominently within the lysine-rich microtubule-binding repeats. Unexpectedly, we identified a unique intrinsic property of tau in which auto-acetylation induces proteolytic tau cleavage, thereby generating distinct N- and C-terminal tau fragments. Supporting a catalytic reaction-based mechanism, mapping and mutagenesis studies showed that tau cysteines, which are required for acetyl group transfer, are also essential for auto-proteolytic tau processing. Further mass spectrometry analysis identified the C-terminal 2nd and 4th microtubule binding repeats as potential sites of auto-cleavage. The identification of acetylation-mediated auto-proteolysis provides a new biochemical mechanism for tau self-regulation and warrants further investigation into whether auto-catalytic functions of tau are implicated in AD and other tauopathies.

  16. PCAF-primed EZH2 acetylation regulates its stability and promotes lung adenocarcinoma progression

    Wan Junhu; Chin Y Eugene; Zhang Hongquan; Zhan Jun; Li Shuai; Ma Ji; Xu Weizhi; Liu Chang; Xue Xiaowei; Xie Yuping; Fang Weigang

    2015-01-01

    Enhancer of zeste homolog 2 ( EZH2 ) is a key epigenetic regulator that catalyzes the trimethyla-tion of H3K27 and is modulated by post-translational modifications (PTMs). However, the precise regulation of EZH2 PTMs remains elusive. We, herein, report that EZH2 is acetylated by acetyltransferase P300/CBP-associat-ed factor (PCAF) and is deacetylated by deacetylase SIRT1. We identified that PCAF interacts with and acetylates EZH2 mainly at lysine 348 (K348). Mechanistically, K348 acetylation decreases EZH2 phosphorylation at T345 and T487 and increases EZH2 stability without disrupting the formation of polycomb repressive complex 2 ( PRC2 ) . Functionally, EZH2 K348 acetylation enhances its capacity in suppression of the target genes and promotes lung cancer cell migration and invasion. Further, elevated EZH2 K348 acetylation in lung adenocarcinoma patients pre-dicts a poor prognosis. Our findings define a new mechanism underlying EZH2 modulation by linking EZH2 acety-lation to its phosphorylation that stabilizes EZH2 and promotes lung adenocarcinoma progression.

  17. Histone H3 globular domain acetylation identifies a new class of enhancers.

    Pradeepa, Madapura M; Grimes, Graeme R; Kumar, Yatendra; Olley, Gabrielle; Taylor, Gillian C A; Schneider, Robert; Bickmore, Wendy A

    2016-06-01

    Histone acetylation is generally associated with active chromatin, but most studies have focused on the acetylation of histone tails. Various histone H3 and H4 tail acetylations mark the promoters of active genes. These modifications include acetylation of histone H3 at lysine 27 (H3K27ac), which blocks Polycomb-mediated trimethylation of H3K27 (H3K27me3). H3K27ac is also widely used to identify active enhancers, and the assumption has been that profiling H3K27ac is a comprehensive way of cataloguing the set of active enhancers in mammalian cell types. Here we show that acetylation of lysine residues in the globular domain of histone H3 (lysine 64 (H3K64ac) and lysine 122 (H3K122ac)) marks active gene promoters and also a subset of active enhancers. Moreover, we find a new class of active functional enhancers that is marked by H3K122ac but lacks H3K27ac. This work suggests that, to identify enhancers, a more comprehensive analysis of histone acetylation is required than has previously been considered. PMID:27089178

  18. The effect of N-acetyl cysteine on laryngopharyngeal reflux.

    Payman Dabirmoghaddam

    2013-11-01

    Full Text Available Laryngopharyngeal reflux (LPR is a variant of gastroesophageal reflux disease (GERD in which the stomach contents go up into the pharynx and then down into the larynx. LPR causes a wide spectrum of manifestations mainly related to the upper and the lower respiratory system such as laryngitis, asthma, chronic obstructive pulmonary disease, cough, hoarseness, postnasal drip disease, sinusitis, otitis media, recurrent pneumonia, laryngeal cancer and etc. The object of this study was to examine the effect of N-acetyl Cysteine (NAC with and without Omeprazole on laryngitis and LPR. Ninety patients with laryngitis or its symptoms were referred and randomly assigned into three groups. The first group was treated by Omeprazole and NAC. The second group was treated by Omeprazole and placebo and the last group was treated by NAC and placebo. Duration of treatment was 3 months and all patients were evaluated at the beginning of study, one month and three month after treatment of sign and symptoms, based on reflux symptom index (RSI and reflex finding score (RFS. Based on the results of this study, despite therapeutic efficacy of all treatment protocols, the RSI before and after 3 months treatment had significant difference in (NAS+ Omeprazole and (Omeprazole+ placebo group (P<0.001 in the first group, P<0.001 in the second group and P=0.35 in the third group. Whereas RFS before and after 3 month treatment had significant difference in all groups. (P<0.001 in each group in comparison with itself but this results had not significant difference after 1 month treatment. Our results showed that the combination therapy with Omeprazole and NAC treatment had the most effect on both subjective and objective questionnaire at least after 3 months treatment. Based on the results of the present study, it seems that the use objective tools are more accurate than subjective tools in evaluation of therapeutic effects in patients with GERD-related laryngitis.

  19. Acetylated α-Tubulin Regulated by N-Acetyl-Seryl-Aspartyl-Lysyl-Proline(Ac-SDKP) Exerts the Anti-fibrotic Effect in Rat Lung Fibrosis Induced by Silica

    Xiaojun, Wang; Yan, Liu; Hong, Xu; Xianghong, Zhang; Shifeng, Li; Dingjie, Xu; Xuemin, Gao; Lijuan, Zhang; Bonan, Zhang; Zhongqiu, Wei; Ruimin, Wang; Brann, Darrell; Fang, Yang

    2016-01-01

    Silicosis is the most serious occupational disease in China. The objective of this study was to screen various proteins related to mechanisms of the pathogenesis of silicosis underlying the anti-fibrotic effect of N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) using proteomic profile analysis. We also aimed to explore a potential mechanism of acetylated α-tubulin (α-Ac-Tub) regulation by Ac-SDKP. Two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/TOF MS) were used to assess the different protein expression profiles between control and silicosis rats treated with or without Ac-SDKP. Twenty-nine proteins were identified to be potentially involved in the progression of silicosis and the anti-fibrotic effect of Ac-SDKP. Our current study finds that 1) the lost expression of Ac-Tub-α may be a new mechanism in rat silicosis; 2) treatment of silicotic rats with N-acetyl-Seryl-Aspartyl-Lysyl-Proline (Ac-SDKP) inhibits myofibroblast differentiation and collagen deposition accompanied by stabilizing the expression of α-Ac-Tub in vivo and in vitro, which is related with deacetylase family member 6 (HDAC6) and α-tubulin acetyl transferase (α-TAT1). Our data suggest that α-Ac-Tub regulation by Ac-SDKP may potentially be a new anti-fibrosis mechanism. PMID:27577858

  20. PSG gene expression is up-regulated by lysine acetylation involving histone and nonhistone proteins.

    Soledad A Camolotto

    Full Text Available BACKGROUND: Lysine acetylation is an important post-translational modification that plays a central role in eukaryotic transcriptional activation by modifying chromatin and transcription-related factors. Human pregnancy-specific glycoproteins (PSG are the major secreted placental proteins expressed by the syncytiotrophoblast at the end of pregnancy and represent early markers of cytotrophoblast differentiation. Low PSG levels are associated with complicated pregnancies, thus highlighting the importance of studying the mechanisms that control their expression. Despite several transcription factors having been implicated as key regulators of PSG gene family expression; the role of protein acetylation has not been explored. METHODOLOGY/PRINCIPAL FINDINGS: Here, we explored the role of acetylation on PSG gene expression in the human placental-derived JEG-3 cell line. Pharmacological inhibition of histone deacetylases (HDACs up-regulated PSG protein and mRNA expression levels, and augmented the amount of acetylated histone H3 associated with PSG 5'regulatory regions. Moreover, PSG5 promoter activation mediated by Sp1 and KLF6, via the core promoter element motif (CPE, -147/-140, was markedly enhanced in the presence of the HDAC inhibitor trichostatin A (TSA. This effect correlated with an increase in Sp1 acetylation and KLF6 nuclear localization as revealed by immunoprecipitation and subcellular fractionation assays. The co-activators PCAF, p300, and CBP enhanced Sp1-dependent PSG5 promoter activation through their histone acetylase (HAT function. Instead, p300 and CBP acetyltransferase domain was dispensable for sustaining co-activation of PSG5 promoter by KLF6. CONCLUSIONS/SIGNIFICANCE: Results are consistent with a regulatory role of lysine acetylation on PSG expression through a relaxed chromatin state and an increase in the transcriptional activity of Sp1 and KLF6 following an augmented Sp1 acetylation and KLF6 nuclear localization.

  1. Catalytic and glycan-binding abilities of ppGalNAc-T2 are regulated by acetylation

    Zlocowski, Natacha; Sendra, Victor G; Lorenz, Virginia; Villarreal, Marcos A; Jorge, Alberto; Núñez, Yolanda; Bennett, Eric P; Clausen, Henrik; Nores, Gustavo A; Irazoqui, Fernando J

    2011-01-01

    ); the first five are located in the catalytic domain. Specific glycosyltransferase activity of ppGalNAc-T2 was reduced 95% by acetylation. The last two amino acids, K521 and S529, are located in the lectin domain, and their acetylation results in alteration of the carbohydrate-binding ability of pp...... activity (catalytic capacity and glycan-binding ability) of ppGalNAc-T2 is regulated by acetylation....

  2. N-Acetylation of L-aspartate in the nervous system: differential distribution of a specific enzyme

    Truckenmiller, M.E.; Namboodiri, M.A.; Brownstein, M.J.; Neale, J.H.

    1985-11-01

    L-Aspartate N-acetyltransferase, a nervous system enzyme that mediates the synthesis of N-acetyl-L-aspartic acid, has been characterized. In the presence of acetyl-CoA, L-aspartate was acetylated 10-fold more efficiently than L-glutamate, and the acetylation of aspartylglutamate was not detectable. Within the nervous system, a 10-fold variation in the enzyme activity was observed, with the brainstem and spinal cord exhibiting the highest activity and retina the lowest detectable activity. No enzyme activity was detected in pituitary, heart, liver, or kidney. The enzyme activity was found to be membrane-associated and was solubilized by treatment with Triton X-100.

  3. Acetyl hexapeptide-3 in a cosmetic formulation acts on skin mechanical properties - clinical study

    Kassandra Azevedo Tadini

    2015-12-01

    Full Text Available abstract Acetyl hexapeptide-3 has been used in anti-aging topical formulations aimed at improving skin appearance. However, few basic studies address its effects on epidermis and dermis, when vehiculated in topical formulations. Thus, the objective of this study was to determine the clinical efficacy of acetyl hexapeptide-3 using biophysical techniques. For this purpose, formulations with and without acetyl hexapeptide-3 were applied to the ventral forearm and the face area of forty female volunteers. Skin conditions were evaluated after 2 and 4-week long daily applications, by analyzing the stratum corneum water content and the skin mechanical properties, using three instruments, the Corneometer(r CM 825, CutometerSEM 575 and ReviscometerRV600. All formulations tested increased the stratum corneum water content in the face region, which remained constant until the end of the study. In contrast, only formulations containing acetyl hexapeptide-3 exhibit a significant effect on mechanical properties, by decreasing the anisotropy of the face skin. No significant effects were observed in viscoelasticity parameters. In conclusion, the effects of acetyl hexapeptide-3 on the anisotropy of face skin characterize the compound as an effective ingredient for improving conditions of the cutaneous tissue, when used in anti-aging cosmetic formulations.

  4. Human borna disease virus infection impacts host proteome and histone lysine acetylation in human oligodendroglia cells

    Liu, Xia [Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016 (China); Department of Neurology, The Fifth People' s Hospital of Shanghai, School of Medicine, Fudan University, Shanghai, 200240 (China); Zhao, Libo [Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016 (China); Department of Neurology, The Third People' s Hospital of Chongqing, 400014 (China); Yang, Yongtao [Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016 (China); Chongqing Key Laboratory of Neurobiology, Chongqing Medical University, Chongqing, 400016 (China); Institute of Neuroscience, Chongqing Medical University, Chongqing, 400016 (China); Bode, Liv [Bornavirus Research Group affiliated to the Free University of Berlin, Berlin (Germany); Huang, Hua [Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016 (China); Chongqing Key Laboratory of Neurobiology, Chongqing Medical University, Chongqing, 400016 (China); Institute of Neuroscience, Chongqing Medical University, Chongqing, 400016 (China); Liu, Chengyu [Chongqing Key Laboratory of Neurobiology, Chongqing Medical University, Chongqing, 400016 (China); Institute of Neuroscience, Chongqing Medical University, Chongqing, 400016 (China); Huang, Rongzhong [Department of Rehabilitative Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, 400010 (China); Zhang, Liang [Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016 (China); Chongqing Key Laboratory of Neurobiology, Chongqing Medical University, Chongqing, 400016 (China); Institute of Neuroscience, Chongqing Medical University, Chongqing, 400016 (China); and others

    2014-09-15

    Background: Borna disease virus (BDV) replicates in the nucleus and establishes persistent infections in mammalian hosts. A human BDV strain was used to address the first time, how BDV infection impacts the proteome and histone lysine acetylation (Kac) of human oligodendroglial (OL) cells, thus allowing a better understanding of infection-driven pathophysiology in vitro. Methods: Proteome and histone lysine acetylation were profiled through stable isotope labeling for cell culture (SILAC)-based quantitative proteomics. The quantifiable proteome was annotated using bioinformatics. Histone acetylation changes were validated by biochemistry assays. Results: Post BDV infection, 4383 quantifiable differential proteins were identified and functionally annotated to metabolism pathways, immune response, DNA replication, DNA repair, and transcriptional regulation. Sixteen of the thirty identified Kac sites in core histones presented altered acetylation levels post infection. Conclusions: BDV infection using a human strain impacted the whole proteome and histone lysine acetylation in OL cells. - Highlights: • A human strain of BDV (BDV Hu-H1) was used to infect human oligodendroglial cells (OL cells). • This study is the first to reveal the host proteomic and histone Kac profiles in BDV-infected OL cells. • BDV infection affected the expression of many transcription factors and several HATs and HDACs.

  5. Effect of (L-Carnitine) on acetyl-L-carnitine production by heart mitochondria

    Bieber, L.L.; Lilly, K.; Lysiak, W.

    1986-05-01

    The authors recently reported a large efflux of acetyl-L-carnitine from rat heart mitochondria during state 3 respiration with pyruvate as substrate both in the presence and absence of malate. In this series of experiments, the effect of the concentration of L-carnitine on the efflux of acetyl-L-carnitine and on the production of /sup 14/CO/sub 2/ from 2-/sup 14/C-pyruvate was determined. Maximum acetylcarnitine production (approximately 25 n moles/min/mg protein) was obtained at 3-5 mM L-carnitine in the absence of added malate. /sup 14/CO/sub 2/ production decreased as the concentration of L-carnitine increased; it plateaued at 3-5 mM L-carnitine. These data indicate carnitine can stimulate flux of pyruvate through pyruvate dehydrogenase and can reduce flux of acetyl CoA through the Krebs cycle by acting as an acceptor of the acetyl moieties of acetyl CoA generated by pyruvate dehydrogenase.

  6. NUCLEOPHOSMIN/B23 NEGATIVELY REGULATES GCN5-DEPENDENT HISTONE ACETYLATION AND TRANSACTIVATION

    Zou, Yonglong [ORNL; Wu, Jun [ORNL; Giannone, Richard J [ORNL; Boucher, Lorrie [Samuel Lunenfeld Res Inst., Canada; Du, Hansen [National Institute on Aging, Baltimore; Huang, Ying [ORNL; Johnson, Dabney K [ORNL; Liu, Yie [National Institute on Aging, Baltimore; Wang, Yisong [ORNL

    2007-01-01

    Nucleophosmin/B23 is a multifunctional phosphoprotein that is overexpressed in cancer cells and has been shown to be involved in both positive and negative regulation of transcription. In this study, we first identified GCN5 acetyltransferase as a B23-interacting protein by mass spectrometry, which was then confirmed by in vivo co-immunoprecipitation. In vitro assay demonstrated that B23 bound the PCAF-N domain of GCN5 and inhibited GCN5-mediated acetylation of both free and mononucleosomal histones, probably through interfering with GCN5 and masking histones from being acetylated. Mitotic B23 exhibited higher inhibitory activity on GCN5-mediated histone acetylation than interphase B23. Immunodepletion experiments of mitotic extracts revealed that phosphorylation of B23 at Thr199 enhanced the inhibition of GCN5-mediated histone acetylation. Moreover, luciferase reporter and microarray analyses suggested that B23 attenuated GCN5-mediated transactivation in vivo. Taken together, our studies suggest a molecular mechanism of B23 in the mitotic inhibition of GCN5-mediated histone acetylation and transactivation.

  7. Acetylation of C/EBPε is a prerequisite for terminal neutrophil differentiation.

    Bartels, Marije; Govers, Anita M; Fleskens, Veerle; Lourenço, Ana Rita; Pals, Cornelieke E; Vervoort, Stephin J; van Gent, Rogier; Brenkman, Arjan B; Bierings, Marc B; Ackerman, Steven J; van Loosdregt, Jorg; Coffer, Paul J

    2015-03-12

    C/EBPε, a member of the CCAAT/enhancer binding protein (C/EBP) family of transcription factors, is exclusively expressed in myeloid cells and regulates transition from the promyelocytic stage to the myelocytic stage of neutrophil development, being indispensable for secondary and tertiary granule formation. Knowledge concerning the functional role of C/EBPε posttranslational modifications is limited to studies concerning phosphorylation and sumoylation. In the current study, using ectopic expression and ex vivo differentiation of CD34(+) hematopoietic progenitor cells, we demonstrate that C/EBPε is acetylated, which was confirmed by mass spectrometry analysis, identifying 4 acetylated lysines in 3 distinct functional domains. Regulation of C/EBPε acetylation levels by the p300 acetyltransferase and the sirtuin 1 deacetylase controls transcriptional activity, which can at least in part be explained by modulation of DNA binding. During neutrophil development, acetylation of lysines 121 and 198 were found to be crucial for terminal neutrophil differentiation and the expression of neutrophil-specific granule proteins, including lactoferrin and collagenase. Taken together, our data illustrate a critical role for acetylation in the functional regulation of C/EBPε activity during terminal neutrophil development. PMID:25568349

  8. Characterization of acetylation of Saccharomyces cerevisiae H2B by mass spectrometry

    Zhang, Kangling

    2008-11-01

    Following the identification of histone H3 modifications in Saccharomyces cerevisiae [K. Zhang, Int. J. Mass Spectrom. 269 (2008) 101-111], here, we report a detailed characterization of post-translational modifications by LC/MS/MS analysis of tryptic and Glu-C digests of H2B proteins isolated from S. cerevisiae. We show that both H2B.1 and H2B.2 are acetylated at K6, K11, K16, K21 and K22 while H2B.2 has an additional acetylation site at K3. All the acetylation sites of yeast H2B except K3 of H2B.2 are located at the same positions on aligned protein sequences of Arabidopsis H2B variants that were reported previously to be acetylated at K6, K11, K27, K32, K38 and K39. A unique acetylation motif AEK is observed in the H2B variants of these two species, indicating a plant/yeast H2B specific acetyltransferase may exist.

  9. Boric acid-dependent decrease in regulatory histone H3 acetylation is not mutagenic in yeast.

    Pointer, Benjamin R; Schmidt, Martin

    2016-07-01

    Candida albicans is a dimorphic yeast commonly found on human mucosal membranes that switches from yeast to hyphal morphology in response to environmental factors. The change to hyphal growth requires histone H3 modifications by the yeast-specific histone acetyltransferase Rtt109. In addition to its role in morphogenesis, Rtt109-dependent acetylation of histone H3 lysine residues 9 and 56 has regulatory functions during DNA replication and repair. Boric acid (BA) is a broad-spectrum agent that specifically inhibits C. albicans hyphal growth, locking the fungus in its harmless commensal yeast state. The present study characterizes the effect of BA on C. albicans histone acetylation in respect to specificity, time-course and significance. We demonstrate that sublethal concentrations of BA reduce H3K9/H3K56 acetylation, both on a basal level and in response to genotoxic stress. Acetylation at other selected histone sites were not affected by BA. qRT-PCR expression analysis of the DNA repair gene Rad51 indicated no elevated level of genotoxic stress during BA exposure. A forward-mutation analysis demonstrated the BA does not increase spontaneous or induced mutations. The findings suggest that DNA repair remains effective even when histone H3 acetylation decreases and dispels the notion that BA treatment impairs genome integrity in yeast. PMID:27190149

  10. Effect of [L-Carnitine] on acetyl-L-carnitine production by heart mitochondria

    The authors recently reported a large efflux of acetyl-L-carnitine from rat heart mitochondria during state 3 respiration with pyruvate as substrate both in the presence and absence of malate. In this series of experiments, the effect of the concentration of L-carnitine on the efflux of acetyl-L-carnitine and on the production of 14CO2 from 2-14C-pyruvate was determined. Maximum acetylcarnitine production (approximately 25 n moles/min/mg protein) was obtained at 3-5 mM L-carnitine in the absence of added malate. 14CO2 production decreased as the concentration of L-carnitine increased; it plateaued at 3-5 mM L-carnitine. These data indicate carnitine can stimulate flux of pyruvate through pyruvate dehydrogenase and can reduce flux of acetyl CoA through the Krebs cycle by acting as an acceptor of the acetyl moieties of acetyl CoA generated by pyruvate dehydrogenase

  11. Radioisotopic assays of CoASH and carnitine and their acetylated forms in human skeletal muscle

    Radioisotopic assays for the determination of acetyl-CoA, CoASH, and acetylcarnitine have been modified for application to the amount of human muscle tissue that can be obtained by needle biopsy. In the last step common to all three methods, acetyl-CoA is condensed with [14C]oxaloacetate by citrate synthase to give [14C]-citrate. For determination of CoASH, CoASH is reacted with acetylphosphate in a reaction catalyzed by phosphotransacetylase to yield acetyl-CoA. In the assay for acetylcarnitine, acetylcarnitine is reacted with CoASH in a reaction catalyzed by carnitine acetyltransferase to form acetyl-CoA. Inclusion of new simple steps in the acetylcarnitine assay and conditions affecting the reliability of all three methods are also described. Acetylcarnitine and free carnitine levels in human rectus abdominis muscle were 3.0 +/- 1.5 (SD) and 13.5 +/- 4.0 mumol/g dry wt, respectively. Values for acetyl-CoA and CoASH were about 500-fold lower, 6.7 +/- 1.8 and 21 +/- 8.9 nmol/g dry wt, respectively. A strong correlation between acetylcarnitine (y) and short-chain acylcarnitine (x), determined as the difference between total and free carnitine, was found in biopsies from the vastus lateralis muscle obtained during intense muscular effort, y = 1.0x + 0.5; r = 0.976

  12. The extracellular release of Schistosoma mansoni HMGB1 nuclear protein is mediated by acetylation

    Coutinho Carneiro, Vitor; Moraes Maciel, Renata de; Caetano de Abreu da Silva, Isabel; Furtado Madeira da Costa, Rodrigo [Instituto de Bioquimica Medica, Programa de Biotecnologia e Biologia Molecular, Universidade Federal do Rio de Janeiro, CCS, Ilha do Fundao, Rio de Janeiro 21941-590 (Brazil); Neto Paiva, Claudia; Torres Bozza, Marcelo [Departamento de Imunologia, Instituto de Microbiologia Professor Paulo de Goes, Universidade Federal do Rio de Janeiro, CCS, Ilha do Fundao, Rio de Janeiro 21941-590 (Brazil); Rosado Fantappie, Marcelo, E-mail: fantappie@bioqmed.ufrj.br [Instituto de Bioquimica Medica, Programa de Biotecnologia e Biologia Molecular, Universidade Federal do Rio de Janeiro, CCS, Ilha do Fundao, Rio de Janeiro 21941-590 (Brazil)

    2009-12-25

    Schistosoma mansoni HMGB1 (SmHMGB1) was revealed to be a substrate for the parasite histone acetyltransferases SmGCN5 and SmCBP1. We found that full-length SmHMGB1, as well as its HMG-box B (but not HMG-box A) were acetylated in vitro by SmGCN5 and SmCBP1. However, SmCBP1 was able to acetylate both substrates more efficiently than SmGCN5. Interestingly, the removal of the C-terminal acidic tail of SmHMGB1 (SmHMGB1{Delta}C) resulted in increased acetylation of the protein. We showed by mammalian cell transfection assays that SmHMGB1 and SmHMGB1{Delta}C were transported from the nucleus to the cytoplasm after sodium butyrate (NaB) treatment. Importantly, after NaB treatment, SmHMGB1 was also present outside the cell. Together, our data suggest that acetylation of SmHMGB1 plays a role in cellular trafficking, culminating with its secretion to the extracellular milieu. The possible role of SmHMGB1 acetylation in the pathogenesis of schistosomiasis is discussed.

  13. Asymmetric distribution of glucose and indole-3-acetyl-myo-inositol in geostimulated Zea mays seedlings

    Momonoki, Y. S.; Bandurski, R. S. (Principal Investigator)

    1988-01-01

    Indole-3-acetyl-myo-inositol occurs in both the kernel and vegetative shoot of germinating Zea mays seedlings. The effect of a gravitational stimulus on the transport of [3H]-5-indole-3-acetyl-myo-inositol and [U-14C]-D-glucose from the kernel to the seedling shoot was studied. Both labeled glucose and labeled indole-3-acetyl-myo-inositol become asymmetrically distributed in the mesocotyl cortex of the shoot with more radioactivity occurring in the bottom half of a horizontally placed seedling. Asymmetric distribution of [3H]indole-3-acetic acid, derived from the applied [3H]indole-3-acetyl-myo-inositol, occurred more rapidly than distribution of total 3H-radioactivity. These findings demonstrate that the gravitational stimulus can induce an asymmetric distribution of substances being transported from kernel to shoot. They also indicate that, in addition to the transport asymmetry, gravity affects the steady state amount of indole-3-acetic acid derived from indole-3-acetyl-myo-inositol.

  14. Proteomic analysis reveals differentially regulated protein acetylation in human amyotrophic lateral sclerosis spinal cord.

    Dong Liu

    Full Text Available Amyotrophic lateral sclerosis (ALS is a progressive fatal neurodegenerative disease that primarily affects motor neurons in the brain and spinal cord. Histone deacetylase (HDAC inhibitors have neuroprotective effects potentially useful for the treatment of neurodegenerative diseases including ALS; however, the molecular mechanisms underlying their potential efficacy is not well understood. Here we report that protein acetylation in urea-soluble proteins is differently regulated in post-mortem ALS spinal cord. Two-dimensional electrophoresis (2-DE analysis reveals several protein clusters with similar molecular weight but different charge status. Liquid chromatography and tandem mass spectrometry (LC-MS/MS identifies glial fibrillary acidic protein (GFAP as the dominant component in the protein clusters. Further analysis indicates six heavily acetylated lysine residues at positions 89, 153, 189, 218, 259 and 331 of GFAP. Immunoprecipitation followed by Western blotting confirms that the larger form of GFAP fragments are acetylated and upregulated in ALS spinal cord. Further studies demonstrate that acetylation of the proteins additional to GFAP is differently regulated, suggesting that acetylation and/or deacetylation play an important role in pathogenesis of ALS.

  15. Human borna disease virus infection impacts host proteome and histone lysine acetylation in human oligodendroglia cells

    Background: Borna disease virus (BDV) replicates in the nucleus and establishes persistent infections in mammalian hosts. A human BDV strain was used to address the first time, how BDV infection impacts the proteome and histone lysine acetylation (Kac) of human oligodendroglial (OL) cells, thus allowing a better understanding of infection-driven pathophysiology in vitro. Methods: Proteome and histone lysine acetylation were profiled through stable isotope labeling for cell culture (SILAC)-based quantitative proteomics. The quantifiable proteome was annotated using bioinformatics. Histone acetylation changes were validated by biochemistry assays. Results: Post BDV infection, 4383 quantifiable differential proteins were identified and functionally annotated to metabolism pathways, immune response, DNA replication, DNA repair, and transcriptional regulation. Sixteen of the thirty identified Kac sites in core histones presented altered acetylation levels post infection. Conclusions: BDV infection using a human strain impacted the whole proteome and histone lysine acetylation in OL cells. - Highlights: • A human strain of BDV (BDV Hu-H1) was used to infect human oligodendroglial cells (OL cells). • This study is the first to reveal the host proteomic and histone Kac profiles in BDV-infected OL cells. • BDV infection affected the expression of many transcription factors and several HATs and HDACs

  16. The Caenorhabditis elegans Elongator complex regulates neuronal alpha-tubulin acetylation.

    Jachen A Solinger

    2010-01-01

    Full Text Available Although acetylated alpha-tubulin is known to be a marker of stable microtubules in neurons, precise factors that regulate alpha-tubulin acetylation are, to date, largely unknown. Therefore, a genetic screen was employed in the nematode Caenorhabditis elegans that identified the Elongator complex as a possible regulator of alpha-tubulin acetylation. Detailed characterization of mutant animals revealed that the acetyltransferase activity of the Elongator is indeed required for correct acetylation of microtubules and for neuronal development. Moreover, the velocity of vesicles on microtubules was affected by mutations in Elongator. Elongator mutants also displayed defects in neurotransmitter levels. Furthermore, acetylation of alpha-tubulin was shown to act as a novel signal for the fine-tuning of microtubules dynamics by modulating alpha-tubulin turnover, which in turn affected neuronal shape. Given that mutations in the acetyltransferase subunit of the Elongator (Elp3 and in a scaffold subunit (Elp1 have previously been linked to human neurodegenerative diseases, namely Amyotrophic Lateral Sclerosis and Familial Dysautonomia respectively highlights the importance of this work and offers new insights to understand their etiology.

  17. The chromosomal protein HMGBI inhibits DNA replication in vitro. The role of post-synthetic acetylation

    The effect of HMGB1 protein on the replication of closed circular plasmid DNA in cell free extract have been studied using parental form of the protein, post-synthetically acetylated HMGB1 and HMGB1 lacking its acidic C-terminal tail. We have shown that HMGB1 protein inhibits DNA replication and that this effect is eliminated upon either acetylation of the protein or removal of the acidic C-terminal domain. An explanation of these findings suggests interactions of HMGB1 with a protein(s) of the replication complex resulting in reduction of its functional efficiency. Acetylation of HMGB1 affects these interactions in a way that restores the initial replication capacity of the system. The eventual protein-protein interactions are supposed to proceed via the C-terminal domain of HMGB1. (authors)

  18. N-terminal acetylation inhibits protein targeting to the endoplasmic reticulum.

    Gabriella M A Forte

    2011-05-01

    Full Text Available Amino-terminal acetylation is probably the most common protein modification in eukaryotes with as many as 50%-80% of proteins reportedly altered in this way. Here we report a systematic analysis of the predicted N-terminal processing of cytosolic proteins versus those destined to be sorted to the secretory pathway. While cytosolic proteins were profoundly biased in favour of processing, we found an equal and opposite bias against such modification for secretory proteins. Mutations in secretory signal sequences that led to their acetylation resulted in mis-sorting to the cytosol in a manner that was dependent upon the N-terminal processing machinery. Hence N-terminal acetylation represents an early determining step in the cellular sorting of nascent polypeptides that appears to be conserved across a wide range of species.

  19. Preparation of Acetylated Guar Gum – Unsaturated Polyester Composites & Effect of Water on Their Properties

    David D’Melo

    2012-07-01

    Full Text Available Guar gum has seen extensive use in blends, however, its application as a filler in thermoset composites has as yet not been investigated. The effect of the addition of guar gum and its acetyl derivatives on the kinetics of water diffusion in unsaturated polyester composites was studied. The effect of water on the mechanical properties of the composites was studied with respect to the nature of filler, filler concentration and time of immersion. All the mechanical properties were observed to decrease on exposure to water. Further, it was observed that acetylated guar gum, with a degree of substitution of 0.21, showed the best mechanical properties, surpassing the other filled composites and that of the pure unsaturated polyester. Thus, acetylated guar gum showed promise as eco-friendly filler in composite formulation.

  20. Aberrant lysine acetylation in tumorigenesis: Implications in the development of therapeutics.

    Kaypee, Stephanie; Sudarshan, Deepthi; Shanmugam, Muthu K; Mukherjee, Debanjan; Sethi, Gautam; Kundu, Tapas K

    2016-06-01

    The 'language' of covalent histone modifications translates environmental and cellular cues into gene expression. This vast array of post-translational modifications on histones are more than just covalent moieties added onto a protein, as they also form a platform on which crucial cellular signals are relayed. The reversible lysine acetylation has emerged as an important post-translational modification of both histone and non-histone proteins, dictating numerous epigenetic programs within a cell. Thus, understanding the complex biology of lysine acetylation and its regulators is essential for the development of epigenetic therapeutics. In this review, we will attempt to address the complexities of lysine acetylation in the context of tumorigenesis, their role in cancer progression and emphasize on the modalities developed to target lysine acetyltransferases towards cancer treatment. PMID:26808162

  1. Polyamine acetylation modulates polyamine metabolic flux, a prelude to broader metabolic consequences.

    Kramer, Debora L; Diegelman, Paula; Jell, Jason; Vujcic, Slavoljub; Merali, Salim; Porter, Carl W

    2008-02-15

    Recent studies suggest that overexpression of the polyamine-acetylating enzyme spermidine/spermine N(1)-acetyltransferase (SSAT) significantly increases metabolic flux through the polyamine pathway. The concept derives from the observation that SSAT-induced acetylation of polyamines gives rise to a compensatory increase in biosynthesis and presumably to increased flow through the pathway. Despite the strength of this deduction, the existence of heightened polyamine flux has not yet been experimentally demonstrated. Here, we use the artificial polyamine precursor 4-fluoro-ornithine to measure polyamine flux by tracking fluorine unit permeation of polyamine pools in human prostate carcinoma LNCaP cells. Conditional overexpression of SSAT was accompanied by a massive increase in intracellular and extracellular acetylated spermidine and by a 6-20-fold increase in biosynthetic enzyme activities. In the presence of 300 microM 4-fluoro-ornithine, SSAT overexpression led to the sequential appearance of fluorinated putrescine, spermidine, acetylated spermidine, and spermine. As fluorinated polyamines increased, endogenous polyamines decreased, so that the total polyamine pool size remained relatively constant. At 24 h, 56% of the spermine pool in the induced SSAT cells was fluorine-labeled compared with only 12% in uninduced cells. Thus, SSAT induction increased metabolic flux by approximately 5-fold. Flux could be interrupted by inhibition of polyamine biosynthesis but not by inhibition of polyamine oxidation. Overall, the findings are consistent with a paradigm whereby flux is initiated by SSAT acetylation of spermine and particularly spermidine followed by a marked increase in key biosynthetic enzymes. The latter sustains the flux cycle by providing a constant supply of polyamines for subsequent acetylation by SSAT. The broader metabolic implications of this futile metabolic cycling are discussed in detail. PMID:18089555

  2. GCN5-dependent acetylation of HIV-1 integrase enhances viral integration

    Albanese Alberto

    2010-03-01

    Full Text Available Abstract Background An essential event during the replication cycle of HIV-1 is the integration of the reverse transcribed viral DNA into the host cellular genome. Our former report revealed that HIV-1 integrase (IN, the enzyme that catalyzes the integration reaction, is positively regulated by acetylation mediated by the histone acetyltransferase (HAT p300. Results In this study we demonstrate that another cellular HAT, GCN5, acetylates IN leading to enhanced 3'-end processing and strand transfer activities. GCN5 participates in the integration step of HIV-1 replication cycle as demonstrated by the reduced infectivity, due to inefficient provirus formation, in GCN5 knockdown cells. Within the C-terminal domain of IN, four lysines (K258, K264, K266, and K273 are targeted by GCN5 acetylation, three of which (K264, K266, and K273 are also modified by p300. Replication analysis of HIV-1 clones carrying substitutions at the IN lysines acetylated by both GCN5 and p300, or exclusively by GCN5, demonstrated that these residues are required for efficient viral integration. In addition, a comparative analysis of the replication efficiencies of the IN triple- and quadruple-mutant viruses revealed that even though the lysines targeted by both GCN5 and p300 are required for efficient virus integration, the residue exclusively modified by GCN5 (K258 does not affect this process. Conclusions The results presented here further demonstrate the relevance of IN post-translational modification by acetylation, which results from the catalytic activities of multiple HATs during the viral replication cycle. Finally, this study contributes to clarifying the recent debate raised on the role of IN acetylated lysines during HIV-1 infection.

  3. ATP-citrate lyase is required for production of cytosolic acetyl coenzyme A and development in Aspergillus nidulans.

    Hynes, Michael J; Murray, Sandra L

    2010-07-01

    Acetyl coenzyme A (CoA) is a central metabolite in carbon and energy metabolism and in the biosynthesis of cellular molecules. A source of cytoplasmic acetyl-CoA is essential for the production of fatty acids and sterols and for protein acetylation, including histone acetylation in the nucleus. In Saccharomyces cerevisiae and Candida albicans acetyl-CoA is produced from acetate by cytoplasmic acetyl-CoA synthetase, while in plants and animals acetyl-CoA is derived from citrate via ATP-citrate lyase. In the filamentous ascomycete Aspergillus nidulans, tandem divergently transcribed genes (aclA and aclB) encode the subunits of ATP-citrate lyase, and we have deleted these genes. Growth is greatly diminished on carbon sources that do not result in cytoplasmic acetyl-CoA, such as glucose and proline, while growth is not affected on carbon sources that result in the production of cytoplasmic acetyl-CoA, such as acetate and ethanol. Addition of acetate restores growth on glucose or proline, and this is dependent on facA, which encodes cytoplasmic acetyl-CoA synthetase, but not on the regulatory gene facB. Transcription of aclA and aclB is repressed by growth on acetate or ethanol. Loss of ATP-citrate lyase results in severe developmental effects, with the production of asexual spores (conidia) being greatly reduced and a complete absence of sexual development. This is in contrast to Sordaria macrospora, in which fruiting body formation is initiated but maturation is defective in an ATP-citrate lyase mutant. Addition of acetate does not repair these defects, indicating a specific requirement for high levels of cytoplasmic acetyl-CoA during differentiation. Complementation in heterokaryons between aclA and aclB deletions for all phenotypes indicates that the tandem gene arrangement is not essential. PMID:20495057

  4. Conformational studies of bacterial peptidoglycan: structure and stereochemistry of N-acetyl-β- D-glucosamine and N-acetyl-β- D-muramic acid

    Yadav, P. N. S.; Rai, D. K.; Yadav, J. S.

    1989-03-01

    The energies of various conformations of N-acetyl-β- D-glucosamine (NAG) and its 3-O- D-lactic acid derivative N-acetyl-β- D-muramic acid (NAM) have been calculated by geometry optimization using the molecular mechanics program MM2. The geometries of these systems have been analyzed in the light of ring torsion, bond lengths, bond angles and conformational states of side groups of the pyranosyl ring and compared with available experimental data of similar pyranose derivatives. The present study indicates the presence of hydrogen bonds to stabilize the side group conformations. Discrepancies with experimental data that are seen in a few cases are ascribed to the nature of the side groups and their geometry.

  5. Cigarette Smoking, N-Acetyltransferase 2 Acetylation Status, and Bladder Cancer Risk

    Marcus, P.M.; Hayes, R.B.; Vineis, P.;

    2000-01-01

    Tobacco use is an established cause of bladder cancer. The ability to detoxify aromatic amines, which are present in tobacco and are potent bladder carcinogens, is compromised in persons with the N-acetyltransferase 2 slow acetylation polymorphism. The relationship of cigarette smoking with bladder...... interaction between smoking and N-acetyltransferase 2 slow acetylation (OR, 1.3; 95% confidence interval, 1.0-1.6) that was somewhat stronger when analyses were restricted to studies conducted in Europe (OR, 1.5; confidence interval, 1.1-1.9), a pooling that included nearly 80% of the collected data. Using...

  6. Mapping Dynamic Histone Acetylation Patterns to Gene Expression in Nanog-Depleted Murine Embryonic Stem Cells

    Airoldi, Edoardo Maria; Markowetz, Florian; Mulder, Klaas; Lemischka, Ihor; Troyanskaya, Olga

    2010-01-01

    Embryonic stem cells (ESC) have the potential to self-renew indefinitely and to differentiate into any of the three germ layers. The molecular mechanisms for self-renewal, maintenance of pluripotency and lineage specification are poorly understood, but recent results point to a key role for epigenetic mechanisms. In this study, we focus on quantifying the impact of histone 3 acetylation (H3K9,14ac) on gene expression in murine embryonic stem cells. We analyze genome-wide histone acetylation p...

  7. Radioimmunoassay for cyclic GMP with femtomole sensitivity using tritiated label and acetylated ligands

    An economical assay using [3H]cyclic GMP is described which will be of use to those laboratories either restricted from using γ isotopes or who do not possess gamma-counting facilities. In this assay, label, standards, and samples are acetylated, and interacted with an antibody raised against the succinyl derivative of cyclic GMP prepared in the usual way. Using this assay procedure 20 fmol of cyclic GMP are detectable. The optimal assay conditions were calculated on theoretical grounds. The use of acetylated ligands might also be applied to the assay of cyclic AMP

  8. Histone Acetyl Transferase (HAT) HBO1 and JADE1 in Epithelial Cell Regeneration

    Havasi, Andrea; Haegele, Joseph A.; Gall, Jonathan M.; Blackmon, Sherry; Ichimura, Takaharu; Bonegio, Ramon G.; Panchenko, Maria V.

    2013-01-01

    HBO1 acetylates lysine residues of histones and is involved in DNA replication and gene transcription. Two isoforms of JADE1, JADE1S and JADE1L, bind HBO1 and promote acetylation of histones in chromatin context. We characterized the role of JADE1-HBO1 complexes in vitro and in vivo during epithelial cell replication. Down-regulation of JADE1 by siRNA diminished the rate of DNA synthesis in cultured cells, decreased endogenous HBO1 protein expression, and prevented chromatin recruitment of re...

  9. Hydrolysis of Wheat Arabinoxylan by Two Acetyl Xylan Esterases from Chaetomium thermophilum

    Tong, Xiaoxue; Lange, Lene; Grell, Morten Nedergaard;

    2015-01-01

    The thermophilic filamentous ascomycete Chaetomium thermophilum produces functionally diverse hemicellulases when grown on hemicellulose as carbon source. Acetyl xylan esterase (EC 3.1.1.72) is an important accessory enzyme in hemicellulose biodegradation. Although the genome of C. thermophilum has...... xylanase treatment and increased to 34 % when xylanase was combined with rCtAxeA and rCtAxeB. In sum, the present study first report the biochemical characterization of two acetyl xylan esterases from C. thermophilum, which are efficient in hydrolyzing hemicellulose with potential application in biomass...

  10. Lysine acetylation can generate highly charged enzymes with increased resistance toward irreversible inactivation

    Shaw, Bryan F; Schneider, Gregory F.; Bilgiçer, Başar; Kaufman, George K.; Neveu, John M.; Lane, William S.; Whitelegge, Julian P.; Whitesides, George M.

    2008-01-01

    This paper reports that the acetylation of lysine ε-NH3 + groups of α-amylase—one of the most important hydrolytic enzymes used in industry—produces highly negatively charged variants that are enzymatically active, thermostable, and more resistant than the wild-type enzyme to irreversible inactivation on exposure to denaturing conditions (e.g., 1 h at 90°C in solutions containing 100-mM sodium dodecyl sulfate). Acetylation also protected the enzyme against irreversible inactivation by the ...

  11. Inhibition effects of acetyl coumarines and thiazole derivatives on corrosion of zinc in acidic medium

    A V Shanbhag; T V Venkatesha; R A Prabhu; B M Praveen

    2011-06-01

    The corrosion inhibition characteristics of acetyl coumarine (AC), bromo acetyl coumarine (BAC) and thiazole derivatives (BTMQ and BTCQ) on the corrosion of zinc in 0.1 M HCl solution were investigated by weight loss, potentiodynamic polarization and impedance techniques. The inhibition efficiency increased with increase in inhibitor concentration upto 5 × 10-4 M, then gave almost same inhibition efficiency. The polarizationmeasurements indicated the mixed nature of inhibitors. The adsorption of compounds obeyed Langmuir’s adsorption isotherm. The thermodynamic functions for adsorption processes were evaluated.

  12. Structures of the N-acetyltransferase domain of Xylella fastidiosa N-acetyl-l-glutamate synthase/kinase with and without a His tag bound to N-acetyl-l-glutamate

    Zhao, Gengxiang; Jin, Zhongmin; Allewell, Norma M.; Tuchman, Mendel; Shi, Dashuang

    2015-01-01

    Structures of the catalytic N-acetyltransferase (NAT) domain of the bifunctional N-acetyl-l-glutamate synthase/kinase (NAGS/K) from Xylella fastidiosa bound to N-acetyl-l-glutamate (NAG) with and without an N-terminal His tag have been solved and refined at 1.7 and 1.4 Å resolution, respectively.

  13. Inhibition of Different Histone Acetyltransferases (HATs) Uncovers Transcription-Dependent and -Independent Acetylation-Mediated Mechanisms in Memory Formation

    Merschbaecher, Katja; Hatko, Lucyna; Folz, Jennifer; Mueller, Uli

    2016-01-01

    Acetylation of histones changes the efficiency of the transcription processes and thus contributes to the formation of long-term memory (LTM). In our comparative study, we used two inhibitors to characterize the contribution of different histone acetyl transferases (HATs) to appetitive associative learning in the honeybee. For one we applied…

  14. New spectrophotometric and radiochemical assays for acetyl-CoA: arylamine N-acetyltransferase applicable to a variety of arylamines

    Simple and sensitive spectrophotometric and radiochemical procedures are described for the assay of acetyl-CoA:arylamine N-acetyltransferase (NAT), which catalyzes the reaction acetyl-CoA + arylamine----N-acetylated arylamine + CoASH. The methods are applicable to crude tissue homogenates and blood lysates. The spectrophotometric assay is characterized by two features: (i) NAT activity is measured by quantifying the disappearance of the arylamine substrate as reflected by decreasing Schiff's base formation with dimethylaminobenzaldehyde. (ii) During the enzymatic reaction, the inhibitory product CoASH is recycled by the system acetyl phosphate/phosphotransacetylase to the substrate acetyl-CoA. The radiochemical procedure depends on enzymatic synthesis of [3H]acetyl-CoA in the assay using [3H]acetate, ATP, CoASH, and acetyl-CoA synthetase. NAT activity is measured by quantifying N-[3H]acetylarylamine after separation from [3H]acetate by extraction. Product inhibition by CoASH is prevented in this system by the use of acetyl-CoA synthetase

  15. NON-DEGRADATIVE DISSOLUTION AND ACETYLATION OF BALL-MILLED PLANT CELL WALLS; HIGH-RESOLUTION SOLUTION-STATE NMR

    We describe two solvent systems for fully dissolving, and optionally derivatizing, finely ground plant cell wall material at room temperature: dimethylsulfoxide and tetrabutylammonium fluoride or N-methylimidazole. In situ acetylation produces acetylated cell walls that are fully soluble in CDCl3. L...

  16. Exploring the Possible Role of Lysine Acetylation on Entamoeba histolytica Virulence: A Focus on the Dynamics of the Actin Cytoskeleton

    L. López-Contreras

    2013-01-01

    Full Text Available Cytoskeleton remodeling can be regulated, among other mechanisms, by lysine acetylation. The role of acetylation on cytoskeletal and other proteins of Entamoeba histolytica has been poorly studied. Dynamic rearrangements of the actin cytoskeleton are crucial for amebic motility and capping formation, processes that may be effective means of evading the host immune response. Here we report the possible effect of acetylation on the actin cytoskeleton dynamics and in vivo virulence of E. histolytica. Using western blot, immunoprecipitation, microscopy assays, and in silico analysis, we show results that strongly suggest that the increase in Aspirin-induced cytoplasm proteins acetylation reduced cell movement and capping formation, likely as a consequence of alterations in the structuration of the actin cytoskeleton. Additionally, intrahepatic inoculation of Aspirin-treated trophozoites in hamsters resulted in severe impairment of the amebic virulence. Taken together, these results suggest an important role for lysine acetylation in amebic invasiveness and virulence.

  17. Lifespan extension and increased resistance to environmental stressors by N-Acetyl-L-Cysteine in Caenorhabditis elegans

    Seung-Il Oh

    2015-05-01

    Full Text Available OBJECTIVE: This study was performed to determine the effect of N-acetyl-L-cysteine, a modified sulfur-containing amino acid that acts as a strong cellular antioxidant, on the response to environmental stressors and on aging in C. elegans. METHOD: The survival of worms under oxidative stress conditions induced by paraquat was evaluated with and without in vivo N-acetyl-L-cysteine treatment. The effect of N-acetyl-L-cysteine on the response to other environmental stressors, including heat stress and ultraviolet irradiation (UV, was also monitored. To investigate the effect on aging, we examined changes in lifespan, fertility, and expression of age-related biomarkers in C. elegans after N-acetyl-L-cysteine treatment. RESULTS: Dietary N-acetyl-L-cysteine supplementation significantly increased resistance to oxidative stress, heat stress, and UV irradiation in C. elegans. In addition, N-acetyl-L-cysteine supplementation significantly extended both the mean and maximum lifespan of C. elegans. The mean lifespan was extended by up to 30.5% with 5 mM N-acetyl-L-cysteine treatment, and the maximum lifespan was increased by 8 days. N-acetyl-L-cysteine supplementation also increased the total number of progeny produced and extended the gravid period of C. elegans. The green fluorescent protein reporter assay revealed that expression of the stress-responsive genes, sod-3 and hsp-16.2, increased significantly following N-acetyl-L-cysteine treatment. CONCLUSION: N-acetyl-L-cysteine supplementation confers a longevity phenotype in C. elegans, possibly through increased resistance to environmental stressors.

  18. Lysine succinylation is a frequently occurring modification in prokaryotes and eukaryotes and extensively overlaps with acetylation

    Weinert, Brian T; Schölz, Christian; Wagner, Sebastian A;

    2013-01-01

    Recent studies have shown that lysines can be posttranslationally modified by various types of acylations. However, except for acetylation, very little is known about their scope and cellular distribution. We mapped thousands of succinylation sites in bacteria (E. coli), yeast (S. cerevisiae), hu...

  19. The effect of N-acetyl-L-cysteine on the viscosity of ileal neobladder mucus.

    Schrier, B.P.; Lichtendonk, W.J.; Witjes, J.A.

    2002-01-01

    N-acetyl-L-cysteine (NAC) proved to be an effective mucolytic in pulmonary secretions. Our goal was to investigate the in vitro effect of NAC on viscosity of ileal neobladder mucus. The urine of a patient with an ileal neobladder was collected during the first 7 days postoperatively and stored in a

  20. Acetylation regulates WRN catalytic activities and affects base excision DNA repair

    Muftuoglu, Meltem; Kusumoto, Rika; Speina, Elzbieta;

    2008-01-01

    The Werner protein (WRN), defective in the premature aging disorder Werner syndrome, participates in a number of DNA metabolic processes, and we have been interested in the possible regulation of its function in DNA repair by post-translational modifications. Acetylation mediated by histone...... acetyltransferases is of key interest because of its potential importance in aging, DNA repair and transcription....

  1. Identification and purification of O-acetyl-L-serine sulphhydrylase in Penicillium chrysogenum

    østergaard, Simon; Theilgaard, Hanne Birgitte; Nielsen, Jens Bredal

    1998-01-01

    -cysteine. The purified enzyme did not catalyse the formation of L-homocysteine from O-acetyl-L-homoserine and sulphide, excluding the possibility that the purified enzyme was O-acetyI-L-homoserine sulphhydrylase with multiple substrate specificity. The purification enhanced the enzymatic specific activity 93-fold...

  2. Binding of the histone chaperone ASF1 to the CBP bromodomain promotes histone acetylation.

    Das, Chandrima; Roy, Siddhartha; Namjoshi, Sarita; Malarkey, Christopher S; Jones, David N M; Kutateladze, Tatiana G; Churchill, Mair E A; Tyler, Jessica K

    2014-03-25

    The multifunctional Creb-binding protein (CBP) protein plays a pivotal role in many critical cellular processes. Here we demonstrate that the bromodomain of CBP binds to histone H3 acetylated on lysine 56 (K56Ac) with higher affinity than to its other monoacetylated binding partners. We show that autoacetylation of CBP is critical for the bromodomain-H3 K56Ac interaction, and we propose that this interaction occurs via autoacetylation-induced conformation changes in CBP. Unexpectedly, the bromodomain promotes acetylation of H3 K56 on free histones. The CBP bromodomain also interacts with the histone chaperone anti-silencing function 1 (ASF1) via a nearby but distinct interface. This interaction is necessary for ASF1 to promote acetylation of H3 K56 by CBP, indicating that the ASF1-bromodomain interaction physically delivers the histones to the histone acetyl transferase domain of CBP. A CBP bromodomain mutation manifested in Rubinstein-Taybi syndrome has compromised binding to both H3 K56Ac and ASF1, suggesting that these interactions are important for the normal function of CBP. PMID:24616510

  3. Proteomic investigations of lysine acetylation identify diverse substrates of mitochondrial deacetylase sirt3

    Sol, E-ri Maria; Wagner, Sebastian A; Weinert, Brian T; Kumar, Amit; Kim, Hyun-Seok; Deng, Chu-Xia; Choudhary, Chuna Ram

    2012-01-01

    KDACs and pinpointing the regulated acetylation sites on target proteins may provide important information about the molecular basis of their functions. Here we apply quantitative proteomics to identify endogenous substrates of the mitochondrial deacetylase Sirtuin 3 (Sirt3) by comparing site...

  4. Acetylation of pregnane X receptor protein determines selective function independent of ligand activation

    Biswas, Arunima; Pasquel, Danielle [Albert Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, NY 10461 (United States); Tyagi, Rakesh Kumar [Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067 (India); Mani, Sridhar, E-mail: sridhar.mani@einstein.yu.edu [Albert Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, NY 10461 (United States)

    2011-03-18

    Research highlights: {yields} Pregnane X receptor (PXR), a major regulatory protein, is modified by acetylation. {yields} PXR undergoes dynamic deacetylation upon ligand-mediated activation. {yields} SIRT1 partially mediates PXR deacetylation. {yields} PXR deacetylation per se induces lipogenesis mimicking ligand-mediated activation. -- Abstract: Pregnane X receptor (PXR), like other members of its class of nuclear receptors, undergoes post-translational modification [PTM] (e.g., phosphorylation). However, it is unknown if acetylation (a major and common form of protein PTM) is observed on PXR and, if it is, whether it is of functional consequence. PXR has recently emerged as an important regulatory protein with multiple ligand-dependent functions. In the present work we show that PXR is indeed acetylated in vivo. SIRT1 (Sirtuin 1), a NAD-dependent class III histone deacetylase and a member of the sirtuin family of proteins, partially mediates deacetylation of PXR. Most importantly, the acetylation status of PXR regulates its selective function independent of ligand activation.

  5. Kinetics of Acid Hydrolysis of Water-Soluble Spruce O-Acetyl Galactoglucomannans

    Xu, C.; Pranovich, A.; Vahasalo, L.; Hemming, J.; Holmbom, B.; Schols, H.A.; Willfor, S.

    2008-01-01

    Water-soluble O-acetyl galactoglucomannan (GGM) is a softwood-derived polysaccharide, which can be extracted on an industrial scale from wood or mechanical pulping waters and now is available in kilogram scale for research and development of value-added products. To develop applications of GGM, info

  6. 2-acetyl-1-pyrroline - key aroma compound in Mediterranean dried sausages

    Stahnke, Marie Louise Heller

    2000-01-01

    Southern types were attributed to a burned coffee odour from smoke in the smoked sausages and a popcorn note in the Mediterranean products covered with mould. The two compounds were 2-furfurylthiol and 2-acetyl-1-pyrroline, respectively. An analysis of five dried, moulded sausages showed that the surface...

  7. Acetylation of pregnane X receptor protein determines selective function independent of ligand activation

    Research highlights: → Pregnane X receptor (PXR), a major regulatory protein, is modified by acetylation. → PXR undergoes dynamic deacetylation upon ligand-mediated activation. → SIRT1 partially mediates PXR deacetylation. → PXR deacetylation per se induces lipogenesis mimicking ligand-mediated activation. -- Abstract: Pregnane X receptor (PXR), like other members of its class of nuclear receptors, undergoes post-translational modification [PTM] (e.g., phosphorylation). However, it is unknown if acetylation (a major and common form of protein PTM) is observed on PXR and, if it is, whether it is of functional consequence. PXR has recently emerged as an important regulatory protein with multiple ligand-dependent functions. In the present work we show that PXR is indeed acetylated in vivo. SIRT1 (Sirtuin 1), a NAD-dependent class III histone deacetylase and a member of the sirtuin family of proteins, partially mediates deacetylation of PXR. Most importantly, the acetylation status of PXR regulates its selective function independent of ligand activation.

  8. Ficolins and FIBCD1: Soluble and membrane bound pattern recognition molecules with acetyl group selectivity

    Thomsen, Theresa; Schlosser, Anders; Holmskov, Uffe;

    2011-01-01

    A network of molecules, which recognizes pathogens, work together to establish a quick and efficient immune response to infectious agents. Molecules containing a fibrinogen related domain in invertebrates and vertebrates have been implicated in immune responses against pathogens, and characterized......D-containing molecules, and discusses structural resemblance but also diversity in recognition of acetylated ligands....

  9. Effect of acetyl-SDKP, an inhibitor of hematopoiesis, in myelosuppressed animals

    The hemoregulatory tetrapeptide Acetyl-SDKP could be used as a myeloprotector in cancer chemotherapy as well as in radiobiology. It improves the survival rate in lethally irradiated rats and stimulates the leucocyte recovery in 1-β-D-arabino-furanosylcytosine treated cynomolgus monkeys

  10. Differential lysine acetylation profiles of Erwinia amylovora strains revealed by proteomics

    Protein lysine acetylation (LysAc) in bacteria has recently been demonstrated to be widespread in E. coli and Salmonella and to broadly regulate bacterial physiology and metabolism. However, LysAc in plant pathogenic bacteria is largely unknown. Here we report the lysine acetylome of Erwinia amylovo...

  11. Micronutrients, N-Acetyl Cysteine, Probiotics and Prebiotics, A Review of Effectiveness in Reducing HIV Progression

    R.B.S. Hummelen (Ruben); J. Hemsworth (Jaimie); G.K. Reid (Gregor)

    2010-01-01

    textabstractLow serum concentrations of micronutrients, intestinal abnormalities, and an inflammatory state have been associated with HIV progression. These may be ameliorated by micronutrients, N-acetyl cysteine, probiotics, and prebiotics. This review aims to integrate the evidence from clinical t

  12. Urinary excretion of N-acetyl-beta-d-glucosaminidase in children.

    Osborne, J.

    1980-01-01

    The normal range for the urinary N-acetyl-beta-D-glucosaminidase/creatinine ratio was determined in 82 children. The range was found to vary with age, and the distribution was found to be logarithmic. This test should help to detect renal tubular disease in children; it gave abnormal results in some of these children.

  13. Hydrolytic stability of water-soluble spruce O-acetyl galactoglucomannans

    Xu, C.; Pranovich, A.; Hemmimg, J.; Holmbom, B.; Albrecht, S.A.; Schols, H.A.; Willfor, S.

    2009-01-01

    Water-soluble native O-acetyl galactoglucomannan (GGM) from spruce is a polysaccharide that can be produced in an industrial scale. To develop GGM applications, information is needed on its stability, particularly under acidic conditions. Therefore, acid hydrolysis of spruce GGM was investigated at

  14. Hydrolysis of wheat B-starch and characterisation of acetylated maltodextrin

    Smrčková, P.; Horský, Jiří; Šárka, E.; Koláček, J.; Netopilík, Miloš; Walterová, Zuzana; Kruliš, Zdeněk; Synytsya, A.; Hrušková, K.

    2013-01-01

    Roč. 98, č. 1 (2013), s. 43-49. ISSN 0144-8617 R&D Projects: GA ČR GA525/09/0607 Institutional research plan: CEZ:AV0Z40500505 Keywords : wheat B-starch * α-amylase * acetylated maltodextrin Subject RIV: JI - Composite Materials Impact factor: 3.916, year: 2013

  15. Arabidopsis NATA1 Acetylates Putrescine and Decreases Defense-Related Hydrogen Peroxide Accumulation1[OPEN

    Preuss, Aileen S.

    2016-01-01

    Biosynthesis of the polyamines putrescine, spermidine, and spermine is induced in response to pathogen infection of plants. Putrescine, which is produced from Arg, serves as a metabolic precursor for longer polyamines, including spermidine and spermine. Polyamine acetylation, which has important regulatory functions in mammalian cells, has been observed in several plant species. Here we show that Arabidopsis (Arabidopsis thaliana) N-ACETYLTRANSFERASE ACTIVITY1 (NATA1) catalyzes acetylation of putrescine to N-acetylputrescine and thereby competes with spermidine synthase for a common substrate. NATA1 expression is strongly induced by the plant defense signaling molecule jasmonic acid and coronatine, an effector molecule produced by DC3000, a Pseudomonas syringae strain that initiates a virulent infection in Arabidopsis ecotype Columbia-0. DC3000 growth is reduced in nata1 mutant Arabidopsis, suggesting a role for NATA1-mediated putrescine acetylation in suppressing antimicrobial defenses. During infection by P. syringae and other plant pathogens, polyamine oxidases use spermidine and spermine as substrates for the production of defense-related H2O2. Compared to wild-type Columbia-0 Arabidopsis, the response of nata1mutants to P. syringae infection includes reduced accumulation of acetylputrescine, greater abundance of nonacetylated polyamines, elevated H2O2 production by polyamine oxidases, and higher expression of genes related to pathogen defense. Together, these results are consistent with a model whereby P. syringae growth is improved in a targeted manner through coronatine-induced putrescine acetylation by NATA1. PMID:27208290

  16. CRE promoter sites modulate alternative splicing via p300-mediated histone acetylation

    Dušková, Eva; Hnilicová, Jarmila; Staněk, David

    2014-01-01

    Roč. 11, č. 7 (2014), s. 865-874. ISSN 1547-6286 R&D Projects: GA ČR(CZ) GBP305/12/G034 Institutional support: RVO:68378050 Keywords : alternative splicing * fibronectin * p300 * histone acetylation * promoter Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.974, year: 2014

  17. The in situ distribution of glycoprotein-bound 4-O-Acetylated sialic acids in vertebrates.

    Aamelfot, Maria; Dale, Ole Bendik; Weli, Simon Chioma; Koppang, Erling Olaf; Falk, Knut

    2014-05-01

    Sialic acids are located at the terminal branches of the cell glycocalyx and secreted glycan molecules. O-Acetylation is an important modification of the sialic acids, however very few studies have demonstrated the in situ distribution of the O-Acetylated sialic acids. Here the distribution of glycoprotein bound 4-O-Acetylated sialic acids (4-O-Ac sias) in vertebrates was determined using a novel virus histochemistry assay. The 4-O-Ac sias were found in the circulatory system, i.e. on the surface of endothelial cells and RBCs, of several vertebrate species, though most frequently in the cartilaginous fish (class Chondrichthyes) and the bony fish (class Osteichthyes). The O-Acetylated sialic acid was detected in 64 % of the examined fish species. Even though the sialic acid was found less commonly in higher vertebrates, it was found at the same location in the positive species. The general significance of this endothelial labelling pattern distribution is discussed. The seemingly conserved local position through the evolution of the vertebrates, suggests an evolutionary advantage of this sialic acid modification. PMID:24833039

  18. Patterns of histone acetylation as targets for novel therapeutic approaches in neurological diseases

    Ebrahimi, Azadeh

    2013-01-01

    Neurological diseases, in particular brain tumors and neurodegenerative disorders, cause significant socio-economic burdens on societies. Exploring epigenetic mechanisms in neurological disorders in recent decades has been an emerging tool for describing the pathogenesis of neurological diseases as well as developing new therapeutics. Global histone acetylation is an epigenetic entity whose alternating patterns in various neurological diseases have recently raised special attention concer...

  19. Nvar-epsilon-acetyl-β-lysine: An osmolyte synthesized by mothanogenic archaebacteria

    Methanosarcina thermophila, a nonmarine methanogenic archaebacterium, can grow in a range of saline concentrations. At less than 0.4 M NaCl, Ms. thermophila accumulated glutamate in response to increasing osmotic stress. At greater than 0.4 M NaCl, this organism synthesized a modified β-amino acid that was identified as Nvar-epsilon-acetyl-β-lysine by NMR spectroscopy and ion-exchange HPLC. This β-amino acid derivative accumulated to high intracellular concentrations (up to 0.6 M) in Ms. thermophila and in another methanogen examined - Methanogenium cariaci, a marine species. The compound has features that are characteristic of a compatible solute: it is neutrally charged at physiological pH and it is highly soluble. When the cells were grown in the presence of exogenous glycine betaine, a physiological pH and it is highly soluble. When the cells were grown in the presence of exogenous glycine betaine, a physiological compatible solute, Nvar-epsilon-acetyl-β-lysine synthesis was repressed and glycine betaine was accumulated. Nvar-epsilon-Acetyl-β-lysine was synthesized by species from three phylogenetic families when grown in high solute concentrations, suggesting that it may be ubiquitous among the methanogens. The ability to control the biosynthesis of Nvar-epsilon-acetyl-β-lysine in response to extracellular solute concentration indicates that the methanogenic archaebacteria have a unique β-amino acid biosynthetic pathway that is osmotically regulated

  20. Production of Nα-acetylated thymosin α1 in Escherichia coli

    Fang Hongqing

    2011-04-01

    Full Text Available Abstract Background Thymosin α1 (Tα1, a 28-amino acid Nα-acetylated peptide, has a powerful general immunostimulating activity. Although biosynthesis is an attractive means of large-scale manufacture, to date, Tα1 can only be chemosynthesized because of two obstacles to its biosynthesis: the difficulties in expressing small peptides and obtaining Nα-acetylation. In this study, we describe a novel production process for Nα-acetylated Tα1 in Escherichia coli. Results To obtain recombinant Nα-acetylated Tα1 efficiently, a fusion protein, Tα1-Intein, was constructed, in which Tα1 was fused to the N-terminus of the smallest mini-intein, Spl DnaX (136 amino acids long, from Spirulina platensis, and a His tag was added at the C-terminus. Because Tα1 was placed at the N-terminus of the Tα1-Intein fusion protein, Tα1 could be fully acetylated when the Tα1-Intein fusion protein was co-expressed with RimJ (a known prokaryotic Nα-acetyltransferase in Escherichia coli. After purification by Ni-Sepharose affinity chromatography, the Tα1-Intein fusion protein was induced by the thiols β-mercaptoethanol or d,l-dithiothreitol, or by increasing the temperature, to release Tα1 through intein-mediated N-terminal cleavage. Under the optimal conditions, more than 90% of the Tα1-Intein fusion protein was thiolyzed, and 24.5 mg Tα1 was obtained from 1 L of culture media. The purity was 98% after a series of chromatographic purification steps. The molecular weight of recombinant Tα1 was determined to be 3107.44 Da by mass spectrometry, which was nearly identical to that of the synthetic version (3107.42 Da. The whole sequence of recombinant Tα1 was identified by tandem mass spectrometry and its N-terminal serine residue was shown to be acetylated. Conclusions The present data demonstrate that Nα-acetylated Tα1 can be efficiently produced in recombinant E. coli. This bioprocess could be used as an alternative to chemosynthesis for the production

  1. 17β-Estradiol regulates histone alterations associated with memory consolidation and increases Bdnf promoter acetylation in middle-aged female mice

    Fortress, Ashley M.; Kim, Jaekyoon; Rachel L Poole; Gould, Thomas J.; Frick, Karyn M.

    2014-01-01

    Histone acetylation is essential for hippocampal memory formation in young adult rodents. Although dysfunctional histone acetylation has been associated with age-related memory decline in male rodents, little is known about whether histone acetylation is altered by aging in female rodents. In young female mice, the ability of 17β-estradiol (E2) to enhance object recognition memory consolidation requires histone H3 acetylation in the dorsal hippocampus. However, the extent to which histone ace...

  2. Missing value imputation for microarray gene expression data using histone acetylation information

    Feng Jihua

    2008-05-01

    Full Text Available Abstract Background It is an important pre-processing step to accurately estimate missing values in microarray data, because complete datasets are required in numerous expression profile analysis in bioinformatics. Although several methods have been suggested, their performances are not satisfactory for datasets with high missing percentages. Results The paper explores the feasibility of doing missing value imputation with the help of gene regulatory mechanism. An imputation framework called histone acetylation information aided imputation method (HAIimpute method is presented. It incorporates the histone acetylation information into the conventional KNN(k-nearest neighbor and LLS(local least square imputation algorithms for final prediction of the missing values. The experimental results indicated that the use of acetylation information can provide significant improvements in microarray imputation accuracy. The HAIimpute methods consistently improve the widely used methods such as KNN and LLS in terms of normalized root mean squared error (NRMSE. Meanwhile, the genes imputed by HAIimpute methods are more correlated with the original complete genes in terms of Pearson correlation coefficients. Furthermore, the proposed methods also outperform GOimpute, which is one of the existing related methods that use the functional similarity as the external information. Conclusion We demonstrated that the using of histone acetylation information could greatly improve the performance of the imputation especially at high missing percentages. This idea can be generalized to various imputation methods to facilitate the performance. Moreover, with more knowledge accumulated on gene regulatory mechanism in addition to histone acetylation, the performance of our approach can be further improved and verified.

  3. Hippocampal histone acetylation regulates object recognition and the estradiol-induced enhancement of object recognition.

    Zhao, Zaorui; Fan, Lu; Fortress, Ashley M; Boulware, Marissa I; Frick, Karyn M

    2012-02-15

    Histone acetylation has recently been implicated in learning and memory processes, yet necessity of histone acetylation for such processes has not been demonstrated using pharmacological inhibitors of histone acetyltransferases (HATs). As such, the present study tested whether garcinol, a potent HAT inhibitor in vitro, could impair hippocampal memory consolidation and block the memory-enhancing effects of the modulatory hormone 17β-estradiol E2. We first showed that bilateral infusion of garcinol (0.1, 1, or 10 μg/side) into the dorsal hippocampus (DH) immediately after training impaired object recognition memory consolidation in ovariectomized female mice. A behaviorally effective dose of garcinol (10 μg/side) also significantly decreased DH HAT activity. We next examined whether DH infusion of a behaviorally subeffective dose of garcinol (1 ng/side) could block the effects of DH E2 infusion on object recognition and epigenetic processes. Immediately after training, ovariectomized female mice received bilateral DH infusions of vehicle, E2 (5 μg/side), garcinol (1 ng/side), or E2 plus garcinol. Forty-eight hours later, garcinol blocked the memory-enhancing effects of E2. Garcinol also reversed the E2-induced increase in DH histone H3 acetylation, HAT activity, and levels of the de novo methyltransferase DNMT3B, as well as the E2-induced decrease in levels of the memory repressor protein histone deacetylase 2. Collectively, these findings suggest that histone acetylation is critical for object recognition memory consolidation and the beneficial effects of E2 on object recognition. Importantly, this work demonstrates that the role of histone acetylation in memory processes can be studied using a HAT inhibitor. PMID:22396409

  4. Preparation and characterization of acetylated starch nanoparticles as drug carrier: Ciprofloxacin as a model.

    Mahmoudi Najafi, Seyed Heydar; Baghaie, Maryam; Ashori, Alireza

    2016-06-01

    The objective of this study was to characterize in-vitro the potential of acetylated corn starch (ACS) particles as a matrix for the delivery of ciprofloxacin (CFx). ACS was successfully synthesized and optimized by the reaction of native corn starch using acetic anhydride and acetic acid with low and high degrees of substitution (DS). The nanoprecipitation method was applied for the formation of the ACS-based nanoparticles, by the dropwise addition of water to acetone solution of ACS under stirring. The effects of acetylation and nanoprecipitation on the morphology and granular structure of ACS samples were examined by the FT-IR, XRD, DSL and SEM techniques. The efficiency of CFx loading was also evaluated via encapsulation efficiency (EE) in ACS nanoparticles. The average degree of acetyl substitution per glucose residue of corn starch was 0.33, 2.00, and 2.66. The nanoparticles size of the ACS and ACS-loaded with CFx were measured and analyzed relative to the solvent:non-solvent ratio. Based on the results, ACS nanoparticles with DS of 2.00 and water:acetone of 3:1 had 312nm diameter. Increasing DS in starch acetate led to increase in the EE from 67.7 to 89.1% and with increasing ratio of water/acetone from 1:1 to 3:1, the EE raised from 48.5 to 89.1%. X-ray diffraction indicated that A-type pattern of native starch was completely transformed into the V-type pattern of acetylated starch. The scanning electron microscopy showed that the different sizes of pores formed on the acetylated starch granules were utterly converted into the uniform-sized spherical nanoparticles after the nanoprecipitation. PMID:26893054

  5. Histone acetylation mediates epigenetic regulation of transcriptional reprogramming in insects during metamorphosis, wounding and infection

    Mukherjee Krishnendu

    2012-10-01

    Full Text Available Abstract Background Gene expression in eukaryotes is regulated by histone acetylation/deacetylation, an epigenetic process mediated by histone acetyltransferases (HATs and histone deacetylases (HDACs whose opposing activities are tightly regulated. The acetylation of histones by HATs increases DNA accessibility and promotes gene expression, whereas the removal of acetyl groups by HDACs has the opposite effect. Results We explored the role of HDACs and HATs in epigenetic reprogramming during metamorphosis, wounding and infection in the lepidopteran model host Galleria mellonella. We measured the expression of genes encoding components of HATs and HDACs to monitor the transcriptional activity of each enzyme complex and found that both enzymes were upregulated during pupation. Specific HAT inhibitors were able to postpone pupation and to reduce insect survival following wounding, whereas HDAC inhibitors accelerated pupation and increased survival. The administration of HDAC inhibitors modulated the expression of effector genes with key roles in tissue remodeling (matrix metalloproteinase, the regulation of sepsis (inhibitor of metalloproteinases from insects and host defense (antimicrobial peptides, and simultaneously induced HAT activity, suggesting that histone acetylation is regulated by a feedback mechanism. We also discovered that both the entomopathogenic fungus Metarhizium anisopliae and the human bacterial pathogen Listeria monocytogenes can delay metamorphosis in G. mellonella by skewing the HDAC/HAT balance. Conclusions Our study provides for the first evidence that pathogenic bacteria can interfere with the regulation of HDACs and HATs in insects which appear to manipulate host immunity and development. We conclude that histone acetylation/deacetylation in insects mediates transcriptional reprogramming during metamorphosis and in response to wounding and infection.

  6. Substituent-specific antibody against glucuronoxylan reveals close association of glucuronic acid and acetyl substituents and distinct labeling patterns in tree species

    Koutaniemi, Sanna; Guillon, Fabienne; Tranquet, Olivier; Bouchet, Brigitte; Tuomainen, Päivi; Virkki, Liisa; Pedersen, Henriette Lodberg; Willats, William George Tycho; Saulnier, Luc; Tenkanen, Maija

    2012-01-01

    antibody binding. The treatment removed acetyl groups from xylan, indicating that the vicinity of glucuronic acid substituents is also acetylated. The novel labeling patterns observed in the xylem of tree species suggested that differences within the cell wall exist both in acetylation degree and in...

  7. 17ß-Estradiol Regulates Histone Alterations Associated with Memory Consolidation and Increases "Bdnf" Promoter Acetylation in Middle-Aged Female Mice

    Fortress, Ashley M.; Kim, Jaekyoon; Poole, Rachel L.; Gould, Thomas J.; Frick, Karyn M.

    2014-01-01

    Histone acetylation is essential for hippocampal memory formation in young adult rodents. Although dysfunctional histone acetylation has been associated with age-related memory decline in male rodents, little is known about whether histone acetylation is altered by aging in female rodents. In young female mice, the ability of 17ß-estradiol…

  8. Binary and tertiary combination of alternariol, 3-acetyl-deoxynivalenol and 15-acetyl-deoxynivalenol on HepG2 cells: Toxic effects and evaluation of degradation products.

    Juan-García, Ana; Juan, Cristina; Manyes, Lara; Ruiz, María-José

    2016-08-01

    Fungi producers of mycotoxins are able to synthesize more than one toxin. Alternariol (AOH) is one of the mycotoxins produced by several Alternaria species, the most common one being Alternaria alternata. The toxins 3-Acetyl-deoxynivalenol (3-ADON) and 15-Acetyl-deoxynivalenol (15-ADON) are acetylated forms of deoxynivalenol (DON) produced by Fusarium graminearum. In the present work it is determined and evaluated the toxic effects of binary and tertiary combination treatment of HepG2 cells with AOH, 3-ADON and 15-ADON, by using the MTT assay (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide), to subsequently apply the isobologram method and elucidate if the mixtures of these mycotoxins produced synergism, antagonism or additive effect; and lastly, to analyze mycotoxins conversion into metabolites produced and released by HepG2 cells after applying the treatment conditions by liquid chromatography tandem mass spectrometry (LC-MS/MS) equipment and extracted from culture media. HepG2 cells were treated at different concentrations over 24, 48 and 72h. IC50 values detected at all times assayed, ranged from 0.8 to >25μM in binary combinations; while in tertiary it ranged from 7.5 to 12μM. Synergistic, antagonism or additive effect detected in the mixtures of these mycotoxins was different depending on low or high concentration. Among all four mycotoxins combinations assayed, 15-ADON+3-ADON presented the highest toxic potential. At all assayed times, recoveries values oscillated depending on the time and combination studied. PMID:27131905

  9. Upregulation of mGlu2 receptors via NF-κB p65 acetylation is involved in the Proneurogenic and antidepressant effects of acetyl-L-carnitine.

    Cuccurazzu, Bruna; Bortolotto, Valeria; Valente, Maria Maddalena; Ubezio, Federica; Koverech, Aleardo; Canonico, Pier Luigi; Grilli, Mariagrazia

    2013-10-01

    Acetyl-L-carnitine (ALC) is a naturally occurring molecule with an important role in cellular bioenergetics and as donor of acetyl groups to proteins, including NF-κB p65. In humans, exogenously administered ALC has been shown to be effective in mood disturbances, with a good tolerability profile. No current information is available on the antidepressant effect of ALC in animal models of depression and on the putative mechanism involved in such effect. Here we report that ALC is a proneurogenic molecule, whose effect on neuronal differentiation of adult hippocampal neural progenitors is independent of its neuroprotective activity. The in vitro proneurogenic effects of ALC appear to be mediated by activation of the NF-κB pathway, and in particular by p65 acetylation, and subsequent NF-κB-mediated upregulation of metabotropic glutamate receptor 2 (mGlu2) expression. When tested in vivo, chronic ALC treatment could revert depressive-like behavior caused by unpredictable chronic mild stress, a rodent model of depression with high face validity and predictivity, and its behavioral effect correlated with upregulated expression of mGlu2 receptor in hippocampi of stressed mice. Moreover, chronic, but not acute or subchronic, drug treatment significantly increased adult born neurons in hippocampi of stressed and unstressed mice. We now propose that this mechanism could be potentially involved in the antidepressant effect of ALC in humans. These results are potentially relevant from a clinical perspective, as for its high tolerability profile ALC may be ideally employed in patient subpopulations who are sensitive to the side effects associated with classical antidepressants. PMID:23670591

  10. Determination of the degree of acetylation and the distribution of acetyl groups in chitosan by HPLC analysis of nitrous acid degraded and PMP labeled products.

    Han, Zhangrun; Zeng, Yangyang; Lu, Hong; Zhang, Lijuan

    2015-09-01

    Chitin is one of the most abundant polysaccharides on earth. It consists of repeating β-1,4 linked N-acetylated glucosamine (A) units. Chitosan is an N-deacetylated product of chitin. Chitosan and its derivatives have broad medical applications as drugs, nutraceuticals, or drug delivery agents. However, a reliable analytical method for quality control of medically used chitosans is still lacking. In current study, nitrous acid was used to cleave all glucosamine residues in chitosan into 2,5-anhydromannose (M) or M at the reducing end of di-, tri-, and oligosaccharides. PMP, i.e. 1-phenyl-3-methyl-5-pyrazolone, was used to label all the Ms. Online UV detection allowed quantification of all M-containing UV peaks whereas online MS analysis directly identified 11 different kinds of mono-, di-, tri-, and oligosaccharides that correlated each oligosaccharide with specific UV peak after HPLC separation. The DA (degree of acetylation) for chitosans was calculated based on the A/(A+M) value derived from the UV data. This newly developed method had several advantages for quality control of chitosan: 1. the experimental procedures were extensively optimized; 2. the reliability of the method was confirmed by online LC-MS analysis; 3. the DA value was obtainable based on the UV data after HPLC analysis, which was comparableto that of (1)H NMR and conductometric titration analyses; 4. finally and most importantly, this method could be used to obtain the DA as well as chemical acetylation/deacetylation mechanisms for chitosan by any laboratory equipped with a HPLC and an online UV detector. PMID:26114886

  11. Impaired Coenzyme A metabolism affects histone and tubulin acetylation in Drosophila and human cell models of pantothenate kinase associated neurodegeneration.

    Siudeja, Katarzyna; Srinivasan, Balaji; Xu, Lanjun; Rana, Anil; de Jong, Jannie; Nollen, Ellen A A; Jackowski, Suzanne; Sanford, Lynn; Hayflick, Susan; Sibon, Ody C M

    2011-12-01

    Pantothenate kinase-associated neurodegeneration (PKAN is a neurodegenerative disease with unresolved pathophysiology. Previously, we observed reduced Coenzyme A levels in a Drosophila model for PKAN. Coenzyme A is required for acetyl-Coenzyme A synthesis and acyl groups from the latter are transferred to lysine residues of proteins, in a reaction regulated by acetyltransferases. The tight balance between acetyltransferases and their antagonistic counterparts histone deacetylases is a well-known determining factor for the acetylation status of proteins. However, the influence of Coenzyme A levels on protein acetylation is unknown. Here we investigate whether decreased levels of the central metabolite Coenzyme A induce alterations in protein acetylation and whether this correlates with specific phenotypes of PKAN models. We show that in various organisms proper Coenzyme A metabolism is required for maintenance of histone- and tubulin acetylation, and decreased acetylation of these proteins is associated with an impaired DNA damage response, decreased locomotor function and decreased survival. Decreased protein acetylation and the concurrent phenotypes are partly rescued by pantethine and HDAC inhibitors, suggesting possible directions for future PKAN therapy development. PMID:21998097

  12. Proteome-wide lysine acetylation in cortical astrocytes and alterations that occur during infection with brain parasite Toxoplasma gondii.

    Anne Bouchut

    Full Text Available Lysine acetylation is a reversible post-translational modification (PTM that has been detected on thousands of proteins in nearly all cellular compartments. The role of this widespread PTM has yet to be fully elucidated, but can impact protein localization, interactions, activity, and stability. Here we present the first proteome-wide survey of lysine acetylation in cortical astrocytes, a subtype of glia that is a component of the blood-brain barrier and a key regulator of neuronal function and plasticity. We identified 529 lysine acetylation sites across 304 proteins found in multiple cellular compartments that largely function in RNA processing/transcription, metabolism, chromatin biology, and translation. Two hundred and seventy-seven of the acetylated lysines we identified on 186 proteins have not been reported previously in any other cell type. We also mapped an acetylome of astrocytes infected with the brain parasite, Toxoplasma gondii. It has been shown that infection with T. gondii modulates host cell gene expression, including several lysine acetyltransferase (KAT and deacetylase (KDAC genes, suggesting that the host acetylome may also be altered during infection. In the T. gondii-infected astrocytes, we identified 34 proteins exhibiting a level of acetylation >2-fold and 24 with a level of acetylation <2-fold relative to uninfected astrocytes. Our study documents the first acetylome map for cortical astrocytes, uncovers novel lysine acetylation sites, and demonstrates that T. gondii infection produces an altered acetylome.

  13. Oxygen-dependent acetylation and dimerization of the corepressor CtBP2 in neural stem cells

    Karaca, Esra; Lewicki, Jakub; Hermanson, Ola, E-mail: Ola.Hermanson@ki.se

    2015-03-01

    The transcriptional corepressor CtBP2 is essential for proper development of the nervous system. The factor exerts its repression by interacting in complexes with chromatin-modifying factors such as histone deacetylases (HDAC) 1/2 and the histone demethylase LSD1/KDM1. Notably, the histone acetyl transferase p300 acetylates CtBP2 and this is an important regulatory event of the activity and subcellular localization of the protein. We recently demonstrated an essential role for CtBPs as sensors of microenvironmental oxygen levels influencing the differentiation potential of neural stem cells (NSCs), but it is not known whether oxygen levels influence the acetylation levels of CtBP factors. Here we show by using proximity ligation assay (PLA) that CtBP2 acetylation levels increased significantly in undifferentiated, proliferating NSCs under hypoxic conditions. CtBP2 interacted with the class III HDAC Sirt1 but this interaction was unaltered in hypoxic conditions, and treatment with the Sirt1 inhibitor Ex527 did not result in any significant change in total CtBP2 acetylation levels. Instead, we revealed a significant decrease in PLA signal representing CtBP2 dimerization in NSCs under hypoxic conditions, negatively correlating with the acetylation levels. Our results suggest that microenvironmental oxygen levels influence the dimerization and acetylation levels, and thereby the activity, of CtBP2 in proliferating NSCs.

  14. Sirt1 physically interacts with Tip60 and negatively regulates Tip60-mediated acetylation of H2AX

    Yamagata, Kazutsune, E-mail: kyamagat@ncc.go.jp [Department of Molecular Oncology Division, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Kitabayashi, Issay [Department of Molecular Oncology Division, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan)

    2009-12-25

    Sirt1 appear to be NAD(+)-dependent deacetylase that deacetylates histones and several non-histone proteins. In this study, we identified Sirt1 as a physical interaction partner of Tip60, which is a mammalian MYST-type histone acetyl-transferase that specifically acetylates histones H2A and H4. Although Tip60 also acetylates DNA damage-specific histone H2A variant H2AX in response to DNA damage, which is a process required for appropriate DNA damage response, overexpression of Sirt1 represses Tip60-mediated acetylation of H2AX. Furthermore, Sirt1 depletion by RNAi causes excessive acetylation of H2AX, and enhances accumulation of {gamma}-ray irradiation-induced MDC1, BRCA1, and Rad51 foci in nuclei. These findings suggest that Sirt1 functions as negative regulator of Tip60-mediated acetylation of H2AX. Moreover, Sirt1 deacetylates an acetylated Tip60 in response to DNA damage and stimulates proteasome-dependent Tip60 degradation in vivo, suggesting that Sirt1 negatively regulates the protein level of Tip60 in vivo. Sirt1 may thus repress excessive activation of the DNA damage response and Rad51-homologous recombination repair by suppressing the function of Tip60.

  15. Pyruvate dehydrogenase and 3-fluoropyruvate: chemical competence of 2-acetylthiamin pyrophosphate as an acetyl group donor to dihydrolipoamide

    The pyruvate dehydrogenase component (E1) of the pyruvate dehydrogenase complex catalyzes the decomposition of 3-fluoropyruvate to CO2, fluoride anion, and acetate. Acetylthiamin pyrophosphate (acetyl-TPP) is an intermediate in this reaction. Incubation of the pyruvate dehydrogenase complex with 3-fluoro[1,2-14]pyruvate, TPP, coenzyme A (CoASH), and either NADH or pyruvate as reducing systems leads to the formation of [14]acetyl-CoA. In this reaction the acetyl group of acetyl-TPP is partitioned by transfer to both CoASH (87 +/- 2%) and water (13 +/- 2%). When the E1 component is incubated with 3-fluoro[1,2-14]pyruvate, TPP, and dihydrolipoamide, [14]acetyldihydrolipoamide is produced. The formation of [14C]acetyldihydrolipoamide was examined as a function of dihydrolipoamide concentration (0.25-16 mM). A plot of the extent of acetyl group partitioning to dihydrolipoamide as a function of 1/[dihydrolipoamide] showed 95 +/- 2% acetyl group transfer to dihydrolipoamide when dihydrolipoamide concentration was extrapolated to infinity. It is concluded that acetyl-TPP is chemically competent as an intermediate for the pyruvate dehydrogenase complex catalyzed oxidative decarboxylation of pyruvate

  16. Spectroscopic and Biological Studies on Newly Synthesized Cobalt (II and Nickel (II Complexes with 2-Acetyl Coumarone Semicarbazone and 2-Acetyl Coumarone Thiosemicarbazone

    Sanjay Goel

    2013-01-01

    Full Text Available Co(II and Ni(II complexes of general composition ML2X2 (M = Co(II, Ni(II; X = Cl−, NO3 − were synthesized by the condensation of metal salts with semicarbazone/thiosemicarbazone derived from 2-acetyl coumarone. The ligands and metal complexes were characterized by NMR, elemental analysis, molar conductance, magnetic susceptibility measurements, IR, and atomic absorption spectral studies. On the basis of electronic, molar conductance and infrared spectral studies, the complexes were found to have square planar geometry. The Schiff bases and their metal complexes were tested for their antibacterial and antioxidant activities.

  17. Stability and Analgesic Efficacy of Di-acetyl Morphine (Diamorphine) Compared with Morphine in Implanted Intrathecal Pumps In Vivo.

    Raphael, Jon H; Palfrey, Stephen M; Rayen, Arasu; Southall, Jane L; Labib, Maurad H

    2004-07-01

    The objective of this study was to investigate di-acetyl morphine as an alternative opioid analgesic for use in implanted intrathecal drug delivery systems because of its greater solubility through evaluation of its stability in vivo and analgesic efficacy in the period between pump refills. Contents of intrathecal drug delivery system reservoirs (SynchroMed, Medtronic, Inc., Minneapolis, MN) that had been filled with di-acetyl morphine dissolved in saline (21), bupivacaine (9), or in both bupivacaine and clonidine (19) were sampled in vivo between 1 and 125 days after refill. The samples were assayed for di-acetyl morphine and its breakdown products by micellar electrokinetic capillary chromatography. Prospective daily numerical pain scores between pump refills, using 11-point Likert scales, on 24 patients with implanted SynchroMed pumps (12 delivering di-acetyl morphine in saline, 12 were delivering morphine in saline) were collected. Results showed that di-acetyl morphine immediately started to decay to mono-acetyl morphine in implanted Synchromed pumps with half-life of 50 days. Mono-acetyl morphine decayed to morphine with a maxima estimated at 125 days. There was no clinically significant change in average weekly pain scores for up to ten weeks in either group (range, 2.5 to 2.8 for diamorphine and 2.7 to 3.1 for morphine) (2-way repeated ANOVA, F(9,220) = 0.98, n.s.). We conclude that di-acetyl morphine and its breakdown products, 6 mono-acetyl morphine and morphine, provide similar analgesia to morphine alone when administered by intrathecal pump for a period of at least ten weeks and may be a useful alternative when a more soluble agent is favored. PMID:22151270

  18. N-Acetyl-L-Leucine Accelerates Vestibular Compensation after Unilateral Labyrinthectomy by Action in the Cerebellum and Thalamus

    Lisa Günther; Roswitha Beck; Guoming Xiong; Heidrun Potschka; Klaus Jahn; Peter Bartenstein; Thomas Brandt; Mayank Dutia; Marianne Dieterich; Michael Strupp; Christian la Fougère; Andreas Zwergal

    2015-01-01

    An acute unilateral vestibular lesion leads to a vestibular tone imbalance with nystagmus, head roll tilt and postural imbalance. These deficits gradually decrease over days to weeks due to central vestibular compensation (VC). This study investigated the effects of i.v. N-acetyl-DL-leucine, N-acetyl-L-leucine and N-acetyl-D-leucine on VC using behavioural testing and serial [18F]-Fluoro-desoxyglucose ([18F]-FDG)-μPET in a rat model of unilateral chemical labyrinthectomy (UL). Vestibular beha...

  19. HBO1 Is Required for H3K14 Acetylation and Normal Transcriptional Activity during Embryonic Development▿

    Kueh, Andrew J.; Dixon, Mathew P.; Voss, Anne K.; Thomas, Tim

    2010-01-01

    We report here that the MYST histone acetyltransferase HBO1 (histone acetyltransferase bound to ORC; MYST2/KAT7) is essential for postgastrulation mammalian development. Lack of HBO1 led to a more than 90% reduction of histone 3 lysine 14 (H3K14) acetylation, whereas no reduction of acetylation was detected at other histone residues. The decrease in H3K14 acetylation was accompanied by a decrease in expression of the majority of genes studied. However, some genes, in particular genes regulati...

  20. On the Mechanism of Condensation between 5-Amino-4, 6-dichloro-2-methylpyrimidine and 1-Acetyl-2-imidazolin-2-one

    2002-01-01

    The condensation reaction between 5-amino-4, 6-dichloro-2-methylpyrimidine and 1-acetyl-2-imidazolin-2-one using POCl3 as solvent gave 4, 6-dichloro-2-methyl-5-(l-acetyl-tetrahydro-imidazo-2-ylidene)-aminopyrimidine predominantly and 4, 6-dichloro-2-methyl-5-{1-[ l-(2-oxo-tetrahydro-imidazolyl)]-acetyene}-aminopyrimidine as by-product. No 4, 6-dichloro-2-methyl-5-(1-acetyl-2-imidazolin-2-yl)-aminopyrimidine was found. The result indicated an esterifi- cation-addition-elimination mechanism.``

  1. Functional Interplay between Acetylation and Methylation of the RelA Subunit of NF-κB▿

    Yang, Xiao-Dong; Tajkhorshid, Emad; Chen, Lin-Feng

    2010-01-01

    Posttranslational modifications of the RelA subunit of NF-κB, including acetylation and methylation, play a key role in controlling the strength and duration of its nuclear activity. Whether these modifications are functionally linked is largely unknown. Here, we show that the acetylation of lysine 310 of RelA impairs the Set9-mediated methylation of lysines 314 and 315, which is important for the ubiquitination and degradation of chromatin-associated RelA. Abolishing the acetylation of lysin...

  2. Functional relevance of novel p300-mediated lysine 314 and 315 acetylation of RelA/p65

    Buerki, C; Rothgiesser, K M; Valovka, T; Owen, H R; Rehrauer, H; Fey, M.; Lane, W S; Hottiger, M O

    2008-01-01

    Nuclear factor kappaB (NF-kappaB) plays an important role in the transcriptional regulation of genes involved in immunity and cell survival. We show here in vitro and in vivo acetylation of RelA/p65 by p300 on lysine 314 and 315, two novel acetylation sites. Additionally, we confirmed the acetylation on lysine 310 shown previously. Genetic complementation of RelA/p65-/- cells with wild type and non-acetylatable mutants of RelA/p65 (K314R and K315R) revealed that neither shuttling, DNA binding...

  3. Inhibition of acetyl-CoA carboxylase by cystamine may mediate the hypotriglyceridemic activity of pantethine.

    McCarty, M F

    2001-03-01

    Pantethine is a versatile and well-tolerated hypolipidemic agent whose efficacy in this regard appears to be mediated by its catabolic product cystamine, a nucleophile which avidly attacks disulfide groups. An overview of pantethine research suggests that the hypotriglyceridemic activity of pantethine reflects cystamine-mediated inhibition of the hepatic acetyl-CoA carboxylase, which can be expected to activate hepatic fatty acid oxidation. Inhibition of HMG-CoA reductase as well as a more distal enzyme in the cholesterol synthetic pathway may account for pantethine's hypocholesterolemic effects. If pantethine does indeed effectively inhibit hepatic acetyl-CoA carboxylase, it may have adjuvant utility in the hepatothermic therapy of obesity. As a safe and effective compound of natural origin, pantethine merits broader use in the management of hyperlipidemias. PMID:11359352

  4. Bromodomains: Translating the words of lysine acetylation into myelin injury and repair.

    Ntranos, Achilles; Casaccia, Patrizia

    2016-06-20

    Bromodomains are evolutionarily highly conserved α-helical structural motifs that recognize and bind acetylated lysine residues. Lysine acetylation is being increasingly recognized as a major posttranslational modification involved in diverse cellular processes and protein interactions and its deregulation has been implicated in the pathophysiology of various human diseases, such as multiple sclerosis and cancer. Bromodomain-containing proteins can have a wide variety of functions, ranging from histone acetyltransferase activity and chromatin remodeling to transcriptional mediation and co-activation. The role of bromodomains in translating a deregulated cell acetylome into disease phenotypes was recently unveiled by the development of small molecule bromodomain inhibitors. This breakthrough discovery highlighted bromodomain-containing proteins as key players of inflammatory pathways responsible for myelin injury and also demonstrated their role in several aspects of myelin repair including oligodendrocyte differentiation and axonal regeneration. PMID:26472704

  5. Synthesis and Molecular Structure of 1-Acetyl-1-(4-iodophenyl)-3-cyclohexylurea

    QIAN Qiu-Feng; ZOU Jian-Ping; MU Xue-Jun; ZENG Run-Sheng

    2006-01-01

    The title compound 1-acetyl-1-(4-iodophenyl)-3-cyclohexylurea 1 (C15H19IN2O2, Mr = 386.22) has been synthesized and its crystal structure was determined by X-ray diffraction analysis. It crystallizes in orthorhombic, space group Pbca, a =15.4754(16), b = 11.4284(11), c = 17.829(2) (A),Z = 8, V = 3153.2(6)(A)3, Dc= 1.627 mg/m3, μ(MoKα) = 2.034 mm-1, F(000) = 1536, the final R = 0.0276 and wR = 0.0593 for 2805 observed reflections (I > 2σ(I)). X-ray analysis reveals that cyclohexyl ring adopts a chair conformation, with the cyclohexyl group located at the 3-position of urea, and the acetyl and 4-iodophenyl groups at the 1-position.

  6. Stereoselective Luche reduction of deoxynivalenol and three of its acetylated derivatives at C8.

    Fruhmann, Philipp; Hametner, Christian; Mikula, Hannes; Adam, Gerhard; Krska, Rudolf; Fröhlich, Johannes

    2014-01-01

    The trichothecene mycotoxin deoxynivalenol (DON) is a well known and common contaminant in food and feed. Acetylated derivatives and other biosynthetic precursors can occur together with the main toxin. A key biosynthetic step towards DON involves an oxidation of the 8-OH group of 7,8-dihydroxycalonectrin. Since analytical standards for the intermediates are not available and these intermediates are therefore rarely studied, we aimed for a synthetic method to invert this reaction, making a series of calonectrin-derived precursors accessible. We did this by developing an efficient protocol for stereoselective Luche reduction at C8. This method was used to access 3,7,8,15-tetrahydroxyscirpene, 3-deacetyl-7,8-dihydroxycalonectrin, 15-deacetyl-7,8-dihydroxycalonectrin and 7,8-dihydroxycalonectrin, which were characterized using several NMR techniques. Beside the development of a method which could basically be used for all type B trichothecenes, we opened a synthetic route towards different acetylated calonectrins. PMID:24434906

  7. (E-(25S-23-Acetyl-5β-furost-22-ene-3β,26-diol

    Sylvain Bernès

    2008-03-01

    Full Text Available The title steroid, C29H46O4, is a furostene derivative with a C=C double-bond length of 1.353 (3 Å and an E configuration. The side chain is oriented toward the α face of the A–E steroidal nucleus and presents a disordered terminal CH2—OH group [occupancies for resolved sites are 0.591 (9 and 0.409 (9]. The methyl group at C20 attached to ring E is also oriented toward the α face, avoiding steric hindrance with the carbonyl O atom of the acetyl group. The furostene and acetyl functionalities form an α,β-unsaturated ketone system, with an s-cis configuration. All hydroxy and carbonyl groups are involved in weak intermolecular hydrogen bonds. The absolute configuration was assigned from the synthesis.

  8. CHITOSAN SOLUTIONS WITH DIFFERENT DEGREES OF ACETYLATION AS COATING ON CUT APPLE

    Douglas de BRITTO

    2012-01-01

    Full Text Available In this study we analyzed the protective properties of different types of chitosan on minimally processed apples, concerning water loss, surface color changes and antifungal activity. Seven different chitosanbased formulations with variable molecular weight and degrees of acetylation were prepared and used to coat sliced apples which were stored in a greenhouse at 28o C and RH 80%. The coatings, with concentration of 2.0g/L, independent of chitosan type, had no significant effect in protecting the samples against loss of mass by water vapor permeation. Along the storage time, all samples resulted in similar dehydration. Gradual browning was observed in cut fruit, whereas chitosan did not maintain natural color of the cut surfaces. Concerning antifungal activity, chitosans with low molecular weight and low degree of acetylation was the best formulation, reducing in around 50% the fungal incidence after 10 days of storage.

  9. Biopolymer-based nanocomposites: effect of lignin acetylation in cellulose triacetate films

    Laura Alicia Manjarrez Nevárez, Lourdes Ballinas Casarrubias, Alain Celzard, Vanessa Fierro, Vinicio Torres Muñoz, Alejandro Camacho Davila, José Román Torres Lubian and Guillermo González Sánchez

    2011-01-01

    Full Text Available We have prepared all-biopolymer nanocomposite films using lignin as a filler and cellulose triacetate (CTA as a polymer matrix, and characterized them by several analytical methods. Three types of lignin were tested: organosolv, hydrolytic and kraft, with or without acetylation. They were used in the form of nanoparticles incorporated at 1 wt% in CTA. Self-supported films were prepared by vapor-induced phase separation at controlled temperature (35–55 °C and relative humidity (10–70%. The efficiency of acetylation of each type of lignin was studied and discussed, as well as its effects on film structure, homogeneity and mechanical properties. The obtained results are explained in terms of intermolecular filler-matrix interaction at the nanometer scale, for which the highest mechanical resistance was reached using hydrolytic lignin in the nanocomposite.

  10. In vivo N-acetyl cysteine reduce hepatocyte death by induced acetaminophen

    Lin, Chih-Ju; Li, Feng-Chieh; Wang, Sheng-Shun; Lee, Hsuan-Shu; Dong, Chen-Yuan

    2011-07-01

    Acetaminophen (APAP) is the famous drug in global, and taking overdose Acetaminophen will intake hepatic cell injure. Desptie substantial progress in our understanding of the mechanism of hepatocellular injury during the last 40 years, many aspects of the pathophysiology are still unknown or controversial.1 In this study, mice are injected APAP overdose to damage hepatocyte. APAP deplete glutathione and ATP of cell, N-Acetyl Cysteine (NAC) plays an important role to protect hepatocytes be injury. N-Acetyl Cysteine provides mitochondrial to produce glutathione to release drug effect hepatocyte. By 6-carboxyfluorescein diacetate (6-CFDA) metabolism in vivo, glutathione keep depleting to observe the hepatocyte morphology in time. Without NAC, cell necrosis increase to plasma membrane damage to release 6-CFDA, that's rupture. After 6-CFDA injection, fluorescence will be retained in hepatocyte. For cell retain with NAC and without NAC are almost the same. With NAC, the number of cell rupture decreases about 75%.

  11. n-Propyl 2,3,4,6-tetra-O-acetyl-β-d-glucopyranoside

    Bettina Mönch

    2013-02-01

    Full Text Available The title compound [systematic name: (2R,3R,4S,5R,6R-2-(acetoxymethyl-6-propoxytetrahydro-2H-pyran-3,4,5-triyl triacetate], C17H26O10, was formed by a Koenigs–Knorr reaction of 2,3,4,6-tetra-O-acetyl-α-d-glucopyranosyl bromide and n-propanol. The central ring adopts a chair conformation. The crystal does not contain any significant interactions such as hydrogen bonds.

  12. PSG Gene Expression Is Up-Regulated by Lysine Acetylation Involving Histone and Nonhistone Proteins

    Camolotto, Soledad A.; Racca, Ana C.; Ridano, Magali E.; Genti-Raimondi, Susana; Panzetta-Dutari, Graciela M.

    2013-01-01

    Background Lysine acetylation is an important post-translational modification that plays a central role in eukaryotic transcriptional activation by modifying chromatin and transcription-related factors. Human pregnancy-specific glycoproteins (PSG) are the major secreted placental proteins expressed by the syncytiotrophoblast at the end of pregnancy and represent early markers of cytotrophoblast differentiation. Low PSG levels are associated with complicated pregnancies, thus highlighting the ...

  13. Histone acetylation deficits in lymphoblastoid cell lines from patients with rubinstein-Taybi syndrome

    López-Atalaya, José P.; Gervasini, Cristina; Mottadelli, Federica; Spena, Silvia; Piccione, Maria A.; Scarano, Gioacchino; Selicorni, Angelo; Barco, Ángel; Larizza, Lidia

    2012-01-01

    Background: Rubinstein-Taybi syndrome (RSTS) is a congenital neurodevelopmental disorder defined by postnatal growth deficiency, characteristic skeletal abnormalities and mental retardation and caused by mutations in the genes encoding for the transcriptional co-activators with intrinsic lysine acetyltransferase (KAT) activity CBP and p300. Previous studies have shown that neuronal histone acetylation is reduced in mouse models of RSTS. Methods: The authors identified different mutations at t...

  14. PROCESS OPTIMIZATION OF TETRA ACETYL ETHYLENE DIAMINE ACTIVATED HYDROGEN PEROXIDE BLEACHING OF POPULUS NIGRA CTMP

    Qiang Zhao; Junwen Pu; Shulei Mao; Guibo Qi

    2010-01-01

    To enhance the bleaching efficiency, the activator of tetra acetyl ethylene diamine (TAED) was used in conventional H2O2 bleaching. The H2O2/TAED bleaching system can accelerate the reaction rate and shorten bleaching time at relative low temperature, which can reduce the production cost. In this research, the process with hydrogen peroxide activated by TAED bleaching of Populus nigra chemi-thermo mechanical pulp was optimized. Suitable bleaching conditions were confirmed as follows: pulp con...

  15. Genome-wide histone acetylation is altered in a transgenic mouse model of Huntington's disease.

    Karen N McFarland

    Full Text Available In Huntington's disease (HD; MIM ID #143100, a fatal neurodegenerative disorder, transcriptional dysregulation is a key pathogenic feature. Histone modifications are altered in multiple cellular and animal models of HD suggesting a potential mechanism for the observed changes in transcriptional levels. In particular, previous work has suggested an important link between decreased histone acetylation, particularly acetylated histone H3 (AcH3; H3K9K14ac, and downregulated gene expression. However, the question remains whether changes in histone modifications correlate with transcriptional abnormalities across the entire transcriptome. Using chromatin immunoprecipitation paired with microarray hybridization (ChIP-chip, we interrogated AcH3-gene interactions genome-wide in striata of 12-week old wild-type (WT and transgenic (TG R6/2 mice, an HD mouse model, and correlated these interactions with gene expression levels. At the level of the individual gene, we found decreases in the number of sites occupied by AcH3 in the TG striatum. In addition, the total number of genes bound by AcH3 was decreased. Surprisingly, the loss of AcH3 binding sites occurred within the coding regions of the genes rather than at the promoter region. We also found that the presence of AcH3 at any location within a gene strongly correlated with the presence of its transcript in both WT and TG striatum. In the TG striatum, treatment with histone deacetylase (HDAC inhibitors increased global AcH3 levels with concomitant increases in transcript levels; however, AcH3 binding at select gene loci increased only slightly. This study demonstrates that histone H3 acetylation at lysine residues 9 and 14 and active gene expression are intimately tied in the rodent brain, and that this fundamental relationship remains unchanged in an HD mouse model despite genome-wide decreases in histone H3 acetylation.

  16. ROS inhibitor N-acetyl-l-cysteine antagonizes the activity of proteasome inhibitors

    Halasi, Marianna; Wang, Ming; Chavan, Tanmay S.; Gaponenko, Vadim; Hay, Nissim; Gartel, Andrei L.

    2013-01-01

    NAC (N-acetyl-l-cysteine) is commonly used to identify and test ROS (reactive oxygen species) inducers, and to inhibit ROS. In the present study, we identified inhibition of proteasome inhibitors as a novel activity of NAC. Both NAC and catalase, another known scavenger of ROS, similarly inhibited ROS levels and apoptosis associated with H2O2. However, only NAC, and not catalase or another ROS scavenger Trolox, was able to prevent effects linked to proteasome inhibition, such as protein stabi...

  17. Sulphoacetaldehyde acetyltransferase yields acetyl phosphate : purification from Alcaligenes defragrans and gene clusters in taurine degradation

    Ruff, Jürgen; Denger, Karin; Cook, Alasdair M.

    2003-01-01

    The facultatively anaerobic bacterium Alcaligenes defragrans NKNTAU was found to oxidize taurine (2-aminoethanesulphonate) with nitrate as the terminal electron acceptor. Taurine was transaminated to 2-sulphoacetaldehyde. This was not converted into sulphite and acetate by a "sulphoacetaldehyde sulpho-lyase" (EC 4.4.1.12), but into sulphite and acetyl phosphate, which was identified by three methods. The enzyme, which required the addition of phosphate, thiamin diphosphate and Mg(2+) ions for...

  18. Autotrophic growth: methylated carbon monoxide dehydrogenase as an intermediate of acetyl-CoA synthesis

    A new pathway of autotrophic growth has been discovered in certain anaerobic bacteria in which acetyl-CoA is the product formed from CO2 for initiation of anabolism rather than 3-phosphoglycerate as in the Calvin Cycle. CO2 is reduced in combination with tetrahydrofolate to methyltetrahydrofolate (CH3THF) and is the source of the CH3 group. CO2 or CO is the source of the carbonyl group. CO dehydrogenase (CODH), corrinoid enzyme, methyltransferase, ferredoxin and CODH disulfide reductase have been isolated from Clostridium thermoaceticum and shown to catalyze the synthesis of acetyl-CoA from CH3THF, CO and CoA. The methyltransferase catalyzes transfer of the CH3 group from CH3THF to the corrinoid enzyme from which the methyl is transferred to CODH. CO is bound to the Ni of CODH forming a Ni-Fe-C center. When CO2 is the source of carbon, H2 and hydrogenase are required for reduction of the CO2 by CODH. CODH disulfide reductase is required for the addition of CoA to the CODH (Pezacka, E. and Wood, H.G. J. Biol. Chem., in press). Then, CODH catalyzes the combination of the three groups forming acetyl-CoA. The authors have now succeeded in methylating CODH using 14CH3I or 14CH3-B12. With the resulting 14CH3-CODH, only CODH disulfide reductase is required for synthesis of [14C]acetyl-CoA from CO and CoA. The amino acid sequence at the CH3-site is being investigated

  19. CHITOSAN SOLUTIONS WITH DIFFERENT DEGREES OF ACETYLATION AS COATING ON CUT APPLE

    Douglas de BRITTO; Maria Fernanda dos SANTOS; Odílio Benedito Garrido ASSIS

    2012-01-01

    In this study we analyzed the protective properties of different types of chitosan on minimally processed apples, concerning water loss, surface color changes and antifungal activity. Seven different chitosanbased formulations with variable molecular weight and degrees of acetylation were prepared and used to coat sliced apples which were stored in a greenhouse at 28o C and RH 80%. The coatings, with concentration of 2.0g/L, independent of chitosan type, had no sign...

  20. N-acetyl-p-benzoquinone imine: a cytochrome P-450-mediated oxidation product of acetaminophen.

    Dahlin, D C; Miwa, G T; Lu, A Y; Nelson, S. D.

    1984-01-01

    N-acetyl-p-benzoquinone imine (NAPQI) has been proposed as the toxic metabolite of acetaminophen for the past 10 years, although it has never been detected as an enzymatic oxidation product of acetaminophen. We report (i) direct detection of NAPQI formed as an oxidation product of acetaminophen by cytochrome P-450 and cumene hydroperoxide and (ii) indirect evidence that is compelling for NAPQI formation from acetaminophen by cytochrome P-450, NADPH, and NADPH-cytochrome P-450 reductase. Evide...

  1. Anti-bis(monoacylglycero)phosphate antibody accumulates acetylated LDL-derived cholesterol in cultured macrophages.

    Delton-Vandenbroucke, Isabelle; Bouvier, Jerome; Makino, Asami; Besson, Nelly; Pageaux, Jean-François; Lagarde, Michel; Kobayashi, Toshihide

    2007-01-01

    Bis(monoacylglycero)phosphate (BMP), also called lysobisphosphatidic acid, is a phospholipid highly enriched in the internal membranes of multivesicular late endosomes, in which it forms specialized lipid domains. It has been suggested that BMP-rich membranes regulate cholesterol transport. Here, we examine the effects of an anti-BMP antibody on cholesterol metabolism and transport in two macrophage cell lines, RAW 264.7 and THP-1, during loading with acetylated low density lipoprotein (AcLDL...

  2. Kinetics of Mushroom Tyrosinase and Melanogenesis Inhibition by N-Acetyl-pentapeptides

    Ching-Yi Lien

    2014-01-01

    Full Text Available We investigated the kinetics of 4N-acetyl-pentapeptides, Ac-P1, Ac-P2, Ac-P3, and Ac-P4, regarding inhibition of mushroom tyrosinase activity. The peptides sequences of Ac-P1, Ac-P2, Ac-P3, and Ac-P4 were Ac-RSRFK, Ac-KSRFR, Ac-KSSFR, and Ac-RSRFS, respectively. The 4N-acetyl-pentapeptides were able to reduce the oxidation of L-DOPA by tyrosinase in a dose-dependent manner. Of the 4N-acetyl-pentapeptides, only Ac-P4 exhibited lag time (80 s at a concentration of 0.5 mg/mL. The tyrosinase inhibitory effects of Ac-P4 (IC50 0.29 mg/mL were more effective than those of Ac-P1, Ac-P2, and Ac-P3, in which IC50s were 0.75 mg/mL, 0.78 mg/mL, and 0.81 mg/mL, respectively. Kinetic analysis demonstrated that all 4N-acetyl-pentapeptides were mixed-type tyrosinase inhibitors. Furthermore, 0.1 mg/mL of Ac-P4 exhibited significant melanogenesis inhibition on B16F10 melanoma cells and was more effective than kojic acid. The melanogenesis inhibition of Ac-P4 was dose-dependent and did not induce any cytotoxicity on B16F10 melanoma cells.

  3. Differential Neuroprotective Effects of Carnosine, Anserine, and N-Acetyl Carnosine against Permanent Focal Ischemia

    Min, Jiangyong; Senut, Marie-Claude; Rajanikant, Krishnamurthy; Greenberg, Eric; Bandagi, Ram; Zemke, Daniel; Mousa, Ahmad; Kassab, Mounzer; Farooq, Muhammad U.; Gupta, Rishi; Majid, Arshad

    2008-01-01

    Carnosine (β-alanyl-L-histidine) has been shown to exhibit neuroprotection in rodent models of cerebral ischemia. In the present study, we further characterized the effects of carnosine treatment in a mouse model of permanent focal cerebral ischemia and compared them with its related peptides anserine and N-acetylated carnosine. We also evaluated the efficacy of bestatin, a carnosinase inhibitor, in ameliorating ischemic brain damage. Permanent focal cerebral ischemia was induced by occlusion...

  4. A unique CE16 acetyl esterase from Podospora anserina active on polymeric xylan.

    Puchart, Vladimír; Berrin, Jean-Guy; Haon, Mireille; Biely, Peter

    2015-12-01

    The genome of the coprophilous fungus Podospora anserina displays an impressive array of genes encoding hemicellulolytic enzymes. In this study, we focused on a putative carbohydrate esterase (CE) from family 16 (CE16) that bears a carbohydrate-binding module from family CBM1. The protein was heterologously expressed in Pichia pastoris and purified to electrophoretic homogeneity. The P. anserina CE16 enzyme (PaCE16A) exhibited different catalytic properties than so far known CE16 esterases represented by the Trichoderma reesei CE16 acetyl esterase (TrCE16). A common property of both CE16 esterases is their exodeacetylase activity, i.e., deesterification at positions 3 and 4 of monomeric xylosides and the nonreducing end xylopyranosyl (Xylp) residue of oligomeric homologues. However, the PaCE16A showed lower positional specificity than TrCE16 and efficiently deacetylated also position 2. The major difference observed between PaCE16A and TrCE16 was found on polymeric substrate, acetylglucuronoxylan. While TrCE16 does not attack internal acetyl groups, PaCE16A deacetylated singly and doubly acetylated Xylp residues in the polymer to such an extent that it resulted in the polymer precipitation. Similarly as typical acetylxylan esterases belonging to CE1, CE4, CE5, and CE6 families, PaCE16A did not attack 3-O-acetyl group of xylopyranosyl residues carrying 4-O-methyl-D-glucuronic acid at position 2. PaCE16A thus represents a CE16 member displaying unique catalytic properties, which are intermediate between the TrCE16 exodeacetylase and acetylxylan esterases designed to deacetylate polymeric substrate. The catalytic versatility of PaCE16A makes the enzyme an important candidate for biotechnological applications. PMID:26329850

  5. Structure of 1,5-Anhydro-D-Fructose: X-ray Analysis of Crystalline Acetylated Dimeric Forms

    Lundt, Inge; Andersen, Søren Møller; Marcussen, Jan; Søtofte, Inger; Yu, Shukun

    1998-01-01

    Acetylation of 1,5-anhydro-D-fructose under acidic conditions gave two crystalline acetylated dimeric forms, which by X-ray analysis were shown to be diastereomeric spiroketals formed between C-2 and C-2´/C-3´. The structures of the compounds differed only at the configuration at C-2. Acetylation...... or benzoylation of 1,5-anhydro-D-fructose in pyridine yielded 3,6-di-O-acetyl-1,5-anhydro-4-deoxy-D-glycero-hex-3-enos-2-ulopyra -nose or crystalline 1,5-anhydro-3,6-di-O-benzoyl-4-deoxy-D-glycero-hex-3-enos-2-ulo-py ranose....

  6. Infrared spectroscopy of the acetyl cation and its protonated ketene isomer

    Mosley, J. D.; Young, J. W.; Duncan, M. A.

    2014-07-01

    [C2,H3,O]+ ions are generated with a pulsed discharge in a supersonic expansion containing methyl acetate or acetone. These ions are mass selected and their infrared spectra are recorded via laser photodissociation and the method of argon tagging. Computational chemistry is employed to investigate structural isomers and their spectra. The acetyl cation (CH3CO+) is the global minimum and protonated ketene (CH2COH+) is the next lowest energy isomer (+176.2 kJ/mol). When methyl acetate is employed as the precursor, the infrared spectrum reveals that only the acetyl cation is formed. Partially resolved rotational structure reveals rotation about the C3 axis. When acetone is used as the precursor, acetyl is still the most abundant cation, but there is also a minor component of protonated ketene. Computations reveal a significant barrier to interconversion between the two isomers (+221 kJ/mol), indicating that protonated ketene must be obtained via kinetic trapping. Both isomers may be present in interstellar environments, and their implications for astrochemistry are discussed.

  7. Acetylated bacterial cellulose coated with urinary bladder matrix as a substrate for retinal pigment epithelium.

    Gonçalves, Sara; Rodrigues, Inês Patrício; Padrão, Jorge; Silva, João Pedro; Sencadas, Vitor; Lanceros-Mendez, Senentxu; Girão, Henrique; Gama, Francisco M; Dourado, Fernando; Rodrigues, Lígia R

    2016-03-01

    This work evaluated the effect of acetylated bacterial cellulose (ABC) substrates coated with urinary bladder matrix (UBM) on the behavior of retinal pigment epithelium (RPE), as assessed by cell adhesion, proliferation and development of cell polarity exhibiting transepithelial resistance and polygonal shaped-cells with microvilli. Acetylation of bacterial cellulose (BC) generated a moderate hydrophobic surface (around 65°) while the adsorption of UBM onto these acetylated substrates did not affect significantly the surface hydrophobicity. The ABS substrates coated with UBM enabled the development of a cell phenotype closer to that of native RPE cells. These cells were able to express proteins essential for their cytoskeletal organization and metabolic function (ZO-1 and RPE65), while showing a polygonal shaped morphology with microvilli and a monolayer configuration. The coated ABC substrates were also characterized, exhibiting low swelling effect (between 1.5-2.0 swelling/mm(3)), high mechanical strength (2048MPa) and non-pyrogenicity (2.12EU/L). Therefore, the ABC substrates coated with UBM exhibit interesting features as potential cell carriers in RPE transplantation that ought to be further explored. PMID:26689643

  8. Reversible Histone Acetylation Involved in Transcriptional Regulation of WT1 Gene

    Yangguang SHAO; Jun LU; Cao CHENG; Liguo CUI; Guoping ZHANG; Baiqu HUANG

    2007-01-01

    To validate the involvement of reversible histone acetylation in the transcriptional regulation of human Wilms' tumor 1 gene (WT1), we analyzed the roles of histone deacetylases (HDACs) and histone acetyltransferase in this epigenetic process. Of the six HDACs (HDAC1-6) examined, HDAC4 and HDAC5 were found to have significant repressing effects on the activity of the WT1 reporter gene, as revealed by luciferase reporter assays and quantitative real-time reverse transcription-polymerase chain reaction assays.Luciferase reporter assays showed that the histone acetyltransferase p300 was able to counteract the HDAC4/HDAC5-mediated repression and that p300/CBP synergized with transcription factors Sp1, c-Myb, and Ets-1 in activation of the WT1 reporter. Chromatin immunoprecipitation experiments showed that p300 promotes the acetylation level of histone H3 at the WT1 intronic enhancer. Based on these data, we proposed a hypothetical model for the involvement of reversible histone acetylation in transcriptional regulation of the WT1 gene. This study provides further insight into the mechanisms of transcriptional regulation of the WT1 gene and WT1-associated diseases treatment.

  9. Pharmacokinetics and acetylation of sulfamethoxazole in turbot Scophthalmus maximus after intravascular administration

    Chang, Zhiqiang; Liu, Fei; Lian, Chun'ang; Zhai, Qianqian; Li, Jian

    2016-07-01

    The pharmacokinetic profiles and sulfamethoxazole (SMX) acetylation process in turbot reared at 18°C were investigated. Either SMX (parent drug) or its acetylized metabolite, N4-acetylsulfamethoxazole (AcSMX), was administered intravascularly to turbot at a dosage of 50 mg/kg BW. Serum concentrations of the parent drug and its metabolite were both measured by HPLC, and the changes in concentration over time were analyzed in two- and non-compartment models because SMX treatment produced multiple peaks. The results demonstrated that the elimination half-life of the parent drugs, SMX and AcSMX, were 159.2 and 5.9 h, respectively. The apparent volume of distribution was 0.2 and 0.8 L/kg, and the clearance was 0.038 and 0.222 L/(h·kg), for SMX and AcSMX, respectively. SMX acetylation in turbot was 2.8%, and the deacetylation of AcSMX was 0.2%. These findings may be useful in optimizing SMX dosage regimens in turbot aquaculture.

  10. Acetylation of oil palm empty fruit bunch fiber as an adsorbent for removal of crude oil.

    Asadpour, Robabeh; Sapari, Nasiman B; Isa, Mohamed Hasnain; Kakooei, Saeid

    2016-06-01

    Removal of oil spillage from the environment is a global concern. Various methods, including the use of fibers as sorbents, have been developed for oil spill control. Oil palm empty fruit bunch (OPEFB) fiber is a plant biomass that may be acetylated by acetic anhydride using N-bromosuccinimide (NBS) as a catalyst; here, the extent of acetylation may be calculated in terms of weight percent gain (WPG). The modified fiber was used to remove Tapis and Arabian crude oils. The optimum time, temperature, and catalyst concentration were 4 h, 120 °C, and 3 %, respectively, and these parameters could achieve an 11.49 % increase in WPG. The optimized parameters improved the adsorption capacity of OPEFB fibers for crude oil removal. The acetylated OPEFB fibers were characterized by using Fourier transform infrared spectroscopy and field emission scanning electron microscopy to observe the functional groups available and morphology. Kinetic and isotherm studies were conducted using different contact times and oil/water ratios. The rate of oil sorption onto the OPEFB fibers can be adequately described by the pseudo-second-order equation. Adsorption studies revealed that adsorption of crude oil on treated OPEFB fiber could be best described by the Langmuir isotherm model. PMID:26944428

  11. Acetylation of alcohols and phenols under solvent-free conditions using iron zirconium phosphate

    Abdol R. Hajipour; Hirbod Karimi; Amir Masti

    2015-01-01

    Iron zirconium phosphate (ZPFe) nanoparticles were found to function as an efficient catalyst for the acetylation of a wide range of alcohols and phenols using acetic anhydride, generating good to excellent yields under solvent‐free conditions. The steric and electronic properties of various sub‐strates had a significant influence on the reaction conditions required to achieve the acetylation. The catalyst used in the current study was characterized by inductively coupled plasma‐optical emission spectrometry, X‐ray diffraction, N2 adsorption‐desorption, scanning electron microscopy, and transmission electron microscopy. These analyses revealed that the interlayer distance in the catalyst increased from 7.5 to 9.3 Å when Fe3+was intercalated between the layers, whereas the crystallinity of the material was reduced. This nanocatalyst could also be recovered and reused at least six times without any discernible decrease in its catalytic activity. This new method for the acetylation of alcohols and phenols has several important advantages, including mild and environ‐mentally friendly reaction conditions, as well as good to excellent yields and a facile work‐up.

  12. VUV photoionization and dissociative photoionization of the prebiotic molecule acetyl cyanide: Theory and experiment

    The present combined theoretical and experimental investigation concerns the single photoionization of gas-phase acetyl cyanide and the fragmentation pathways of the resulting cation. Acetyl cyanide (AC) is inspired from both the chemistry of cyanoacetylene and the Strecker reaction which are thought to be at the origin of medium sized prebiotic molecules in the interstellar medium. AC can be formed by reaction from cyanoacetylene and water but also from acetaldehyde and HCN or the corresponding radicals. In view of the interpretation of vacuum ultraviolet (VUV) experimental data obtained using synchrotron radiation, we explored the ground potential energy surface (PES) of acetyl cyanide and of its cation using standard and recently implemented explicitly correlated methodologies. Our PES covers the regions of tautomerism (between keto and enol forms) and of the lowest fragmentation channels. This allowed us to deduce accurate thermochemical data for this astrobiologically relevant molecule. Unimolecular decomposition of the AC cation turns out to be very complex. The implications for the evolution of prebiotic molecules under VUV irradiation are discussed

  13. VUV photoionization and dissociative photoionization of the prebiotic molecule acetyl cyanide: Theory and experiment

    Bellili, A.; Hochlaf, M., E-mail: hochlaf@univ-mlv.fr, E-mail: martin.schwell@lisa.u-pec.fr [Laboratoire Modélisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, Université Paris-Est, 5 bd Descartes, 77454 Marne-la-Vallée (France); Schwell, M., E-mail: hochlaf@univ-mlv.fr, E-mail: martin.schwell@lisa.u-pec.fr; Bénilan, Y.; Fray, N.; Gazeau, M.-C. [Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), UMR 7583 CNRS, Institut Pierre et Simon Laplace, Universités Paris-Est Créteil et Paris Diderot, 61 Avenue du Général de Gaulle, 94010 Créteil (France); Mogren Al-Mogren, M. [Chemistry Department, Faculty of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Guillemin, J.-C. [Institut des Sciences Chimiques de Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France); Poisson, L. [Laboratoire Francis Perrin, CNRS URA 2453, CEA, IRAMIS, Laboratoire Interactions Dynamique et Lasers, Bât 522, F-91191 Gif/Yvette (France)

    2014-10-07

    The present combined theoretical and experimental investigation concerns the single photoionization of gas-phase acetyl cyanide and the fragmentation pathways of the resulting cation. Acetyl cyanide (AC) is inspired from both the chemistry of cyanoacetylene and the Strecker reaction which are thought to be at the origin of medium sized prebiotic molecules in the interstellar medium. AC can be formed by reaction from cyanoacetylene and water but also from acetaldehyde and HCN or the corresponding radicals. In view of the interpretation of vacuum ultraviolet (VUV) experimental data obtained using synchrotron radiation, we explored the ground potential energy surface (PES) of acetyl cyanide and of its cation using standard and recently implemented explicitly correlated methodologies. Our PES covers the regions of tautomerism (between keto and enol forms) and of the lowest fragmentation channels. This allowed us to deduce accurate thermochemical data for this astrobiologically relevant molecule. Unimolecular decomposition of the AC cation turns out to be very complex. The implications for the evolution of prebiotic molecules under VUV irradiation are discussed.

  14. MOF Acetylates the Histone Demethylase LSD1 to Suppress Epithelial-to-Mesenchymal Transition.

    Luo, Huacheng; Shenoy, Anitha K; Li, Xuehui; Jin, Yue; Jin, Lihua; Cai, Qingsong; Tang, Ming; Liu, Yang; Chen, Hao; Reisman, David; Wu, Lizi; Seto, Edward; Qiu, Yi; Dou, Yali; Casero, Robert A; Lu, Jianrong

    2016-06-21

    The histone demethylase LSD1 facilitates epithelial-to-mesenchymal transition (EMT) and tumor progression by repressing epithelial marker expression. However, little is known about how its function may be modulated. Here, we report that LSD1 is acetylated in epithelial but not mesenchymal cells. Acetylation of LSD1 reduces its association with nucleosomes, thus increasing histone H3K4 methylation at its target genes and activating transcription. The MOF acetyltransferase interacts with LSD1 and is responsible for its acetylation. MOF is preferentially expressed in epithelial cells and is downregulated by EMT-inducing signals. Expression of exogenous MOF impedes LSD1 binding to epithelial gene promoters and histone demethylation, thereby suppressing EMT and tumor invasion. Conversely, MOF depletion enhances EMT and tumor metastasis. In human cancer, high MOF expression correlates with epithelial markers and a favorable prognosis. These findings provide insight into the regulation of LSD1 and EMT and identify MOF as a critical suppressor of EMT and tumor progression. PMID:27292636

  15. MOF Acetylates the Histone Demethylase LSD1 to Suppress Epithelial-to-Mesenchymal Transition

    Huacheng Luo

    2016-06-01

    Full Text Available The histone demethylase LSD1 facilitates epithelial-to-mesenchymal transition (EMT and tumor progression by repressing epithelial marker expression. However, little is known about how its function may be modulated. Here, we report that LSD1 is acetylated in epithelial but not mesenchymal cells. Acetylation of LSD1 reduces its association with nucleosomes, thus increasing histone H3K4 methylation at its target genes and activating transcription. The MOF acetyltransferase interacts with LSD1 and is responsible for its acetylation. MOF is preferentially expressed in epithelial cells and is downregulated by EMT-inducing signals. Expression of exogenous MOF impedes LSD1 binding to epithelial gene promoters and histone demethylation, thereby suppressing EMT and tumor invasion. Conversely, MOF depletion enhances EMT and tumor metastasis. In human cancer, high MOF expression correlates with epithelial markers and a favorable prognosis. These findings provide insight into the regulation of LSD1 and EMT and identify MOF as a critical suppressor of EMT and tumor progression.

  16. Acetyl-lysine erasers and readers in the control of pulmonary hypertension and right ventricular hypertrophy

    Stratton, Matthew S.; McKinsey, Timothy A.

    2016-01-01

    Acetylation of lysine residues within nucleosomal histone tails provides a crucial mechanism for epigenetic control of gene expression. Acetyl groups are coupled to lysine residues by histone acetyltransferases (HATs) and removed by histone deacetylases (HDACs), which are also commonly referred to as “writers” and “erasers”, respectively. In addition to altering the electrostatic properties of histones, lysine acetylation often creates docking sites for bromodomain-containing “reader” proteins. This review focuses on epigenetic control of pulmonary hypertension (PH) and associated right ventricular (RV) cardiac hypertrophy and failure. Effects of small molecule HDAC inhibitors in pre-clinical models of PH are highlighted. Furthermore, we describe the recently discovered role of bromodomain and extraterminal (BET) reader proteins in the control of cardiac hypertrophy, and provide evidence suggesting that one member of this family, BRD4, contributes to the pathogenesis of RV failure. Together, the data suggest intriguing potential for pharmacological epigenetic therapies for the treatment of PH and right-sided heart failure. PMID:25707943

  17. Differential lysine acetylation profiles of Erwinia amylovora strains revealed by proteomics.

    Wu, Xia; Vellaichamy, Adaikkalam; Wang, Dongping; Zamdborg, Leonid; Kelleher, Neil L; Huber, Steven C; Zhao, Youfu

    2013-02-21

    Protein lysine acetylation (LysAc) has recently been demonstrated to be widespread in E. coli and Salmonella, and to broadly regulate bacterial physiology and metabolism. However, LysAc in plant pathogenic bacteria is largely unknown. Here we first report the lysine acetylome of Erwinia amylovora, an enterobacterium causing serious fire blight disease of apples and pears. Immunoblots using generic anti-lysine acetylation antibodies demonstrated that growth conditions strongly affected the LysAc profiles in E. amylovora. Differential LysAc profiles were also observed for two E. amylovora strains, known to have differential virulence in plants, indicating translational modification of proteins may be important in determining virulence of bacterial strains. Proteomic analysis of LysAc in two E. amylovora strains identified 141 LysAc sites in 96 proteins that function in a wide range of biological pathways. Consistent with previous reports, 44% of the proteins are involved in metabolic processes, including central metabolism, lipopolysaccharide, nucleotide and amino acid metabolism. Interestingly, for the first time, several proteins involved in E. amylovora virulence, including exopolysaccharide amylovoran biosynthesis- and type III secretion-associated proteins, were found to be lysine acetylated, suggesting that LysAc may play a major role in bacterial virulence. Comparative analysis of LysAc sites in E. amylovora and E. coli further revealed the sequence and structural commonality for LysAc in the two organisms. Collectively, these results reinforce the notion that LysAc of proteins is widespread in bacterial metabolism and virulence. PMID:23234799

  18. Acetylation reduces SOX9 nuclear entry and ACAN gene transactivation in human chondrocytes.

    Bar Oz, Michal; Kumar, Ashok; Elayyan, Jinan; Reich, Eli; Binyamin, Milana; Kandel, Leonid; Liebergall, Meir; Steinmeyer, Juergen; Lefebvre, Veronique; Dvir-Ginzberg, Mona

    2016-06-01

    Changes in the content of aggrecan, an essential proteoglycan of articular cartilage, have been implicated in the pathophysiology of osteoarthritis (OA), a prevalent age-related, degenerative joint disease. Here, we examined the effect of SOX9 acetylation on ACAN transactivation in the context of osteoarthritis. Primary chondrocytes freshly isolated from degenerated OA cartilage displayed lower levels of ACAN mRNA and higher levels of acetylated SOX9 compared with cells from intact regions of OA cartilage. Degenerated OA cartilage presented chondrocyte clusters bearing diffused immunostaining for SOX9 compared with intact cartilage regions. Primary human chondrocytes freshly isolated from OA knee joints were cultured in monolayer or in three-dimensional alginate microbeads (3D). SOX9 was hypo-acetylated in 3D cultures and displayed enhanced binding to a -10 kb ACAN enhancer, a result consistent with higher ACAN mRNA levels than in monolayer cultures. It also co-immunoprecipitated with SIRT1, a major deacetylase responsible for SOX9 deacetylation. Finally, immunofluorescence assays revealed increased nuclear localization of SOX9 in primary chondrocytes treated with the NAD SIRT1 cofactor, than in cells treated with a SIRT1 inhibitor. Inhibition of importin β by importazole maintained SOX9 in the cytoplasm, even in the presence of NAD. Based on these data, we conclude that deacetylation promotes SOX9 nuclear translocation and hence its ability to activate ACAN. PMID:26910618

  19. Dynamics of DNA methylation and Histone H4 acetylation during floral bud differentiation in azalea

    Valledor Luis

    2010-01-01

    Full Text Available Abstract Background The ability to control the timing of flowering is a key strategy for planning production in ornamental species such as azalea, however it requires a thorough understanding of floral transition. Floral transition is achieved through a complex genetic network and regulated by multiple environmental and endogenous cues. Dynamic changes between chromatin states facilitating or inhibiting DNA transcription regulate the expression of floral induction pathways in response to environmental and developmental signals. DNA methylation and histone modifications are involved in controlling the functional state of chromatin and gene expression. Results The results of this work indicate that epigenetic mechanisms such as DNA methylation and histone H4 acetylation have opposite and particular dynamics during the transition from vegetative to reproductive development in the apical shoots of azalea. Global levels of DNA methylation and histone H4 acetylation as well as immunodetection of 5-mdC and acetylated H4, in addition to a morphological study have permitted the delimitation of four basic phases in the development of the azalea bud and allowed the identification of a stage of epigenetic reprogramming which showed a sharp decrease of whole DNA methylation similar to that is defined in other developmental processes in plants and in mammals. Conclusion The epigenetic control and reorganization of chromatin seem to be decisive for coordinating floral development in azalea. DNA methylation and H4 deacetylation act simultaneously and co-ordinately, restructuring the chromatin and regulating the gene expression during soot apical meristem development and floral differentiation.

  20. Butyrate-induced GPR41 Activation Inhibits Histone Acetylation and Cell Growth

    Jin Wu; Zongli Zhou; Yinghe Hu; Suzhen Dong

    2012-01-01

    Butyrate has been recently identified as a natural ligand of the G-protein-coupled receptor 41 (GPR41).In addition,it is an inhibitor of histone deacetylase (HDAC).Butyrate treatment results in the hyperacetylation of histones,with resultant multiple biological effects including inhibition of proliferation,induction of cell cycle arrest,and apoptosis,in a variety of cultured mammalian cells.However,it is not clear whether GPR41 is actively involved in the above-mentioned processes.In this study,we generated a stable cell line expressing the hGPR41 receptor in order to investigate the involvement of GPR41 on butyrate-induced biochemical and physiologic processes.We found that GPR41 activation may be a compensatory mechanism to counter the increase in histone H3 acetylation levels induced by butyrate treatment.Moreover,GPR41 had an inhibitory effect on the anti-proliferative,pro-apoptotic effects of butyrate.GPR41 expression induced cell cycle arrest at the Gl-stage,while its activation by butyrate can cause more cells to pass the Gl checkpoint.These results indicated that GPR41 was associated with histone acetylation and might be involved in the acetylation-related regulation of cell processes including proliferation,apoptosis,and the cell cycle.

  1. 2-Aminofluorene metabolism and DNA adduct formation by mononuclear leukocytes from rapid and slow acetylator mouse strains.

    Levy, G N; Chung, J G; Weber, W W

    1994-02-01

    Following exposure of mice to the arylamine carcinogen 2-aminofluorene, DNA-carcinogen adducts can be found in the target tissues liver and bladder, and also in circulating leukocytes. Evidence is presented here that mouse mononuclear leukocytes (MNL) are capable of metabolizing 2-aminofluorene to DNA-binding metabolites which give rise to the adducts found in the MNL. Both lymphocytes and monocytes were able to acetylate arylamines during 18 h of culture. The degree of acetylation was determined by the N-acetyltransferase genotype of the mice as shown through use of acetylator congenic strains which differ only in the Nat-2 gene. Cultured MNL from rapid acetylator mice (C57BL/6J and A.B6-Natr) produced about twice as much N-acetylaminofluorene from 2-aminofluorene and 6- to 8-fold as much N-acetyl-p-aminobenzoic acid from p-aminobenzoic acid as cells from slow acetylator mice (B6.A-Nat(s) and A/J). Other differences in arylamine metabolism by MNL in culture were observed and shown to be due to genetic factors, currently unidentified, other than N-acetyltransferase. DNA adduct formation following incubation of MNL with the arylamine carcinogen 2-aminofluorene was related to both acetylation capacity and to other genetic metabolic factors in the mouse genome. MNL from rapid acetylator mice with the C57BL/6J background (B6) had 3-fold the DNA adduct levels of cells from the corresponding slow acetylator congenic (B6.A-Nat(s)). Similarly, MNL from rapid acetylator mice with the A/J background (A.B6-Natr) had twice the DNA adduct levels of those from their corresponding slow congenic (A). Adduct levels in MNL from C57BL/6J were nearly the same as those of MNL from A/J, again indicating the involvement of loci other than acetylation in DNA adduct formation. The finding of genetically dependent arylamine carcinogen metabolism and DNA adduct formation in cultured MNL suggests the possibility of using cultured MNL for assessing individual susceptibility to arylamine

  2. H3K9 acetylation change patterns in rats after exposure to traffic-related air pollution.

    Ding, Rui; Jin, Yongtang; Liu, Xinneng; Zhu, Ziyi; Zhang, Yuan; Wang, Ting; Xu, Yinchun

    2016-03-01

    Traffic-related air pollution (TRAP) has been acknowledged as a potential risk factor for numerous respiratory disorders including lung cancer; however, the exact mechanisms involved are still unclear. Here we investigated the effects of TRAP exposure on the H3K9 acetylation in rats. The exposure was performed in both spring and autumn with identical study procedures. In each season, 48 healthy Wistar rats were exposed to different levels of TRAP for 4h, 7d, 14d, and 28d, respectively. H3K9 acetylation levels in both the peripheral blood mononuclear cells (PBMCs) and lung tissues were quantified. Multiple linear regression was applied to assess the influence of air pollutants on H3K9 acetylation levels. The levels of PM2.5, PM10, and NO2 in the tunnel and crossroad groups were significantly higher than in the control group. The H3K9 acetylation levels were not significantly different between spring and autumn. When spring and autumn data were analyzed together, no significant association between the TRAP and H3K9 acetylation was found in 4h exposure window. However, in the 7d exposure window, PM2.5 and PM10 exposures were associated with changes in H3K9 acetylation ranging from 0.276 (0.053, 0.498) to 0.475 (0.103, 0.848) per 1μg/m(3) increase in the pollutant concentration. In addition, prolonged exposure of the rats in the tunnel showed that both PM2.5 and PM10 concentrations were positively associated with H3k9 acetylation in both PBMCs and lung tissues. The findings showed that 7-d and prolonged TRAP exposure could effectively increase the H3K9 acetylation level in both PBMCs and lung tissues of rats. PMID:26855416

  3. Comparison of Catalysts Preyssler and Silica-Supported Nano Preyssler in the Synthesis of Acetyl Salicylic Acid

    Nazari, H.; A. Ahmadpour; Bamoharram, F. F.; M. M. Heravi; Eslami, N.

    2012-01-01

    The extensive demand for cleaner environment is forcing chemical industry to use less hazardous materials. In this regard, heteropolyacids attracted considerable amount of interest due to the less toxic behavior in addition of possessing higher acidity. Heteropoly acids have been used as catalysts for the reaction of salicylic acid with acetic anhydride. The performance of different forms of heteropoly acids in the presence of acetic anhydride as acetylating agent for acetylation of salicylic...

  4. High specific activity N-Acetyl-3H-α-Aspartyl- L-Glutamic at micro mole scale

    High specific activity N-Acetyl-3H- α -Aspartyl-I-Glutamic acid at micro mole scale in prepared acetylating L- α -Aspartyl-L-glutamic with 3H-acetic anhydride in re distilled toluene. The product le purified through cationic and anionic columns. The radiochemical purity as determined by thin-layer chromatography is greater then 99% at the time preparation. (Author) 5 refs

  5. Arginine Biosynthesis in Thermotoga maritima: Characterization of the Arginine-Sensitive N-Acetyl-l-Glutamate Kinase

    Fernández-Murga, M. Leonor; Gil-Ortiz, Fernando; Llácer, José L.; Rubio, Vicente

    2004-01-01

    To help clarify the control of arginine synthesis in Thermotoga maritima, the putative gene (argB) for N-acetyl-l-glutamate kinase (NAGK) from this microorganism was cloned and overexpressed, and the resulting protein was purified and shown to be a highly thermostable and specific NAGK that is potently and selectively inhibited by arginine. Therefore, NAGK is in T. maritima the feedback control point of arginine synthesis, a process that in this organism involves acetyl group recycling and ap...

  6. Crystal Structure of TDP-Fucosamine Acetyl Transferase (WECD) from Escherichia Coli, an Enzyme Required for Enterobacterial Common Antigen Synthesis

    Enterobacterial common antigen (ECA) is a polysaccharide found on the outer membrane of virtually all gram-negative enteric bacteria and consists of three sugars, N-acetyl-D-glucosamine, N-acetyl-D-mannosaminuronic acid, and 4-acetamido-4,6-dideoxy-D-galactose, organized into trisaccharide repeating units having the sequence →(3)-α-D-Fuc4NAc-(1→4)-β-D-ManNAcA-(1→4)-α-D-GlcNAc-(1→). While the precise function of ECA is unknown, it has been linked to the resistance of Shiga-toxin-producing Escherichia coli (STEC) O157:H7 to organic acids and the resistance of Salmonella enterica to bile salts. The final step in the synthesis of 4-acetamido-4,6-dideoxy-D-galactose, the acetyl-coenzyme A (CoA)-dependent acetylation of the 4-amino group, is carried out by TDP-fucosamine acetyltransferase (WecD). We have determined the crystal structure of WecD in apo form at a 1.95-Angstroms resolution and bound to acetyl-CoA at a 1.66-Angstroms resolution. WecD is a dimeric enzyme, with each monomer adopting the GNAT N-acetyltransferase fold, common to a number of enzymes involved in acetylation of histones, aminoglycoside antibiotics, serotonin, and sugars. The crystal structure of WecD, however, represents the first structure of a GNAT family member that acts on nucleotide sugars. Based on this cocrystal structure, we have used flexible docking to generate a WecD-bound model of the acetyl-CoA-TDP-fucosamine tetrahedral intermediate, representing the structure during acetyl transfer. Our structural data show that WecD does not possess a residue that directly functions as a catalytic base, although Tyr208 is well positioned to function as a general acid by protonating the thiolate anion of coenzyme A.

  7. P/CAF-mediated acetylation regulates the function of the basic helix–loop–helix transcription factor TAL1/SCL

    Huang, Suming; Qiu, Yi; Shi, Yubin; Xu, Zhixiong; Brandt, Stephen J.

    2000-01-01

    The basic helix–loop–helix transcription factor TAL1 (or SCL) is a critical regulator of hematopoietic and vascular development and is misexpressed in the majority of patients with T-cell acute lymphoblastic leukemia. We found previously that TAL1 could interact with transcriptional co-activator and co-repressor complexes possessing histone acetyltransferase and deacetylase activities, respectively. Here, we report that TAL1 is subject to acetylation in vivo and can be acetylated by p300 and ...

  8. Mass Transfer and Chemical Reaction Approach of the Kinetics of the Acetylation of Gadung Flour using Glacial Acetic Acid

    Andri Cahyo Kumoro

    2015-03-01

    Full Text Available Acetylation is one of the common methods of modifying starch properties by introducing acetil (CH3CO groups to starch molecules at low temperatures. While most acetylation is conducted using starch as anhidroglucose source and acetic anhydride or vinyl acetate as nucleophilic agents, this work employ reactants, namely flour and glacial acetic acid. The purpose of this work are to study the effect of pH reaction and GAA/GF mass ratio on the rate of acetylation reaction and to determine its rate constants. The acetylation of gadung flour with glacial acetic acid in the presence of sodium hydroxide as a homogenous catalyst was studied at ambient temperature with pH ranging from 8-10 and different mass ratio of acetic acid : gadung flour (1:3; 1:4; and 1:5. It was found that increasing pH, lead to increase the degree of substitution, while increasing GAA/GF mass ratio caused such decreases in the degree of substitution, due to the hydrolysis of the acetylated starch. The desired starch acetylation reaction is accompanied by undesirable hydrolysis reaction of the acetylated starch after 40-50 minutes reaction time. Investigation of kinetics of the reaction observed that the value of mass transfer rate constant (Kcs is smaller than the surface reaction rate constant (k. Thus, it can be concluded that rate controlling step is mass transfer.  © 2015 BCREC UNDIP. All rights reservedReceived: 7th August 2014; Revised: 8th September 2014; Accepted: 14th September 2014How to Cite: Kumoro, A.C., Amelia, R. (2015. Mass Transfer and Chemical Reaction Approach of the Kinetics of the Acetylation of Gadung Flour using Glacial Acetic Acid. Bulletin of Chemical Reaction Engineering & Catalysis, 10 (1: 30-37. (doi:10.9767/bcrec.10.1.7181.30-37Permalink/DOI: http://dx.doi.org/10.9767/bcrec.10.1.7181.30-37

  9. Synthesis of spiro[indolo-1,5-benzodiazepines] from 3-acetyl coumarins for use as possible antianxiety agents

    Raviraj A Kusanur; Manjunath Ghate; Manohar V Kulkarni

    2004-08-01

    3-Acetyl coumarins (1) when allowed react with isatin (2) gave corresponding 3-(3'-hydroxy-2'-oxo indolo) acetyl coumarins (3), which on dehydration afforded the corresponding ,-unsaturated ketones (4). Cyclocondensation of (4) with substituted -phenylene diamines resulted in novel 3-coumarinyl spiro[indolo-1,5-benzodiazepines] (5). Structures of all the compounds have been established on the basis of their IR, NMR and mass spectral data and have been screened for their antimicrobial activity and antianxiety activity in mice.

  10. Acetylation of TUG protein promotes the accumulation of GLUT4 glucose transporters in an insulin-responsive intracellular compartment.

    Belman, Jonathan P; Bian, Rachel R; Habtemichael, Estifanos N; Li, Don T; Jurczak, Michael J; Alcázar-Román, Abel; McNally, Leah J; Shulman, Gerald I; Bogan, Jonathan S

    2015-02-13

    Insulin causes the exocytic translocation of GLUT4 glucose transporters to stimulate glucose uptake in fat and muscle. Previous results support a model in which TUG traps GLUT4 in intracellular, insulin-responsive vesicles termed GLUT4 storage vesicles (GSVs). Insulin triggers TUG cleavage to release the GSVs; GLUT4 then recycles through endosomes during ongoing insulin exposure. The TUG C terminus binds a GSV anchoring site comprising Golgin-160 and possibly other proteins. Here, we report that the TUG C terminus is acetylated. The TUG C-terminal peptide bound the Golgin-160-associated protein, ACBD3 (acyl-CoA-binding domain-containing 3), and acetylation reduced binding of TUG to ACBD3 but not to Golgin-160. Mutation of the acetylated residues impaired insulin-responsive GLUT4 trafficking in 3T3-L1 adipocytes. ACBD3 overexpression enhanced the translocation of GSV cargos, GLUT4 and insulin-regulated aminopeptidase (IRAP), and ACBD3 was required for intracellular retention of these cargos in unstimulated cells. Sirtuin 2 (SIRT2), a NAD(+)-dependent deacetylase, bound TUG and deacetylated the TUG peptide. SIRT2 overexpression reduced TUG acetylation and redistributed GLUT4 and IRAP to the plasma membrane in 3T3-L1 adipocytes. Mutation of the acetylated residues in TUG abrogated these effects. In mice, SIRT2 deletion increased TUG acetylation and proteolytic processing. During glucose tolerance tests, glucose disposal was enhanced in SIRT2 knock-out mice, compared with wild type controls, without any effect on insulin concentrations. Together, these data support a model in which TUG acetylation modulates its interaction with Golgi matrix proteins and is regulated by SIRT2. Moreover, acetylation of TUG enhances its function to trap GSVs within unstimulated cells and enhances insulin-stimulated glucose uptake. PMID:25561724

  11. Fate of the fragrance material acetyl cedrene in sediment inhabited by the benthic molluscs Macoma balthica and Mya arenaria

    Baral, Kaushal; Burdukovska, Valentina; David, Minodora; Kærhus Olufsen, Mads

    2013-01-01

    In recent time it has come to concern that hydrophobic organic compounds, from the relatively large group of fragrance materials, enter the aquatic environment via drainage systems and bioaccumulate in the sediment and biota. Acetyl cedrene is one of these compounds. In this report the fate and effects of acetyl cedrene were studied on two species of marine molluscs – Macoma balthica and Mya arenaria – with different feeding strategies. An experiment was conducted over a period of 14 days, af...

  12. Autotrophic growth: the methyl binding site of CO dehydrogenase in the synthesis of acetyl-CoA

    A pathway in which CO or CO2 and H2 is used as a source of energy and carbon to synthesize acetyl-CoA is used for autotrophic growth of acetogenes, methanogens and some sulfate-reducing bacteria. All enzymes involved in this pathway have been purified from C. thermoaceticum. Five of them: CO dehydrogenase (CODH), corrinoid protein, methyltransferase, CODH disulfide reductase (SSRd) and ferredoxin catalyzed synthesis of acetyl-CoA from methyltetrahydrofolate, CO and CoA. CODH is a central enzyme catalyzing the condensation of CH3, CO and CoA and per se it catalyzes a reversible exchange of CO with acetyl-CoA. Thus, CODH must have binding sites for CH3, CO and CoA. They have succeeded in methylating β subunits of CODH using 14CH3I or 14CH-corrinoid protein, a native donor of the CH3 group in synthesis of acetyl-CoA. With resulting [14CH3]CODH, only SSRd is required for synthesis of [14C]acetyl-CoA from CO and CoA. The kinetic studies show that CH3I is a competitive inhibitor for exchange reaction between CO and acetyl-CoA. Acetaldehyde and acetyl-CoA but not acetic acid and CoA protected CODH against methylation by CH3I. Methyl group bound to CODH is very slowly removed by CO and CoA and acetyl-CoA accelerated this process. These data confirm that CH3 group from CH3I and CH3-corrinoid protein is bound to the methyl binding site of CODH

  13. Activation of the aryl hydrocarbon receptor by carcinogenic aromatic amines and modulatory effects of their N-acetylated metabolites.

    Juricek, Ludmila; Bui, Linh-Chi; Busi, Florent; Pierre, Stéphane; Guyot, Erwan; Lamouri, Aazdine; Dupret, Jean-Marie; Barouki, Robert; Coumoul, Xavier; Rodrigues-Lima, Fernando

    2015-12-01

    Aromatic amines (AAs) are an important class of chemicals which account for 12 % of known carcinogens. The biological effects of AAs depend mainly on their biotransformation into reactive metabolites or into N-acetylated metabolites which are generally considered as less toxic. Although the activation of the aryl hydrocarbon receptor (AhR) pathway by certain carcinogenic AAs has been reported, the effects of their N-acetylated metabolites on the AhR have not been addressed. Here, we investigated whether carcinogenic AAs and their N-acetylated metabolites may activate/modulate the AhR pathway in the absence and/or the presence of a bona fide AhR ligand (benzo[a]pyrene/B(a)P]. In agreement with previous studies, we found that certain AAs activated the AhR in human liver and lung cells as assessed by an increase in cytochrome P450 1A1 (CYP1A1) expression and activity. Altogether, we report for the first time that these properties can be modulated by the N-acetylation status of the AA. Whereas 2-naphthylamine significantly activated the AhR and induced CYP1A1 expression, its N-acetylated metabolite was less efficient. In contrast, the N-acetylated metabolite of 2-aminofluorene was able to significantly activate AhR, whereas the parent AA, 2-aminofluorene, did not. In the presence of B(a)P, activation of AhR or antagonist effects were observed depending on the AA or its N-acetylated metabolite. Activation and/or modulation of the AhR pathway by AAs and their N-acetylated metabolites may represent a novel mechanism contributing to the toxicological effects of AAs. More broadly, our data suggest biological interactions between AAs and other classes of xenobiotics through the AhR pathway. PMID:25224404

  14. Interactions between N-acetyl-L-cysteine protected CdTe quantum dots and doxorubicin through spectroscopic method

    Yang, Xiupei, E-mail: xiupeiyang@163.com [Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, Nanchong 637000 (China); College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637000 (China); Lin, Jia; Liao, Xiulin; Zong, Yingying; Gao, Huanhuan [College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637000 (China)

    2015-06-15

    Highlights: • CdTe quantum dots with the diameter of 3–5 nm were synthesized in aqueous solution. • The modified CdTe quantum dots showed well fluorescence properties. • The interaction between the CdTe quantum dots and doxorubicin (DR) was investigated. - Abstract: N-acetyl-L-cysteine protected cadmium telluride quantum dots with a diameter of 3–5 nm were synthesized in aqueous solution. The interaction between N-acetyl-L-cysteine/cadmium telluride quantum dots and doxorubicin was investigated by ultraviolet–visible absorption and fluorescence spectroscopy at physiological conditions (pH 7.2, 37 °C). The results indicate that electron transfer has occurred between N-acetyl-L-cysteine/cadmium telluride quantum dots and doxorubicin under light illumination. The quantum dots react readily with doxorubicin to form a N-acetyl-L-cysteine/cadmium telluride-quantum dots/doxorubicin complex via electrostatic attraction between the −NH{sub 3}{sup +} moiety of doxorubicin and the −COO{sup −} moiety of N-acetyl-L-cysteine/cadmium telluride quantum dots. The interaction of N-acetyl-L-cysteine/cadmium telluride-quantum dots/doxorubicin complex with bovine serum albumin was studied as well, showing that the complex might induce the conformation change of bovine serum due to changes in microenvironment of bovine serum.

  15. The PHD finger of p300 influences its ability to acetylate histone and non-histone targets.

    Rack, Johannes G M; Lutter, Timo; Kjæreng Bjerga, Gro Elin; Guder, Corina; Ehrhardt, Christine; Värv, Signe; Ziegler, Mathias; Aasland, Rein

    2014-12-12

    In enzymes that regulate chromatin structure, the combinatorial occurrence of modules that alter and recognise histone modifications is a recurrent feature. In this study, we explored the functional relationship between the acetyltransferase domain and the adjacent bromodomain/PHD finger (bromo/PHD) region of the transcriptional coactivator p300. We found that the bromo/PHD region of p300 can bind to the acetylated catalytic domain in vitro and augment the catalytic activity of the enzyme. Deletion of the PHD finger, but not the bromodomain, impaired the ability of the enzyme to acetylate histones in vivo, whilst it enhanced p300 self-acetylation. A point mutation in the p300 PHD finger that is related to the Rubinstein-Taybi syndrome resulted in increased self-acetylation but retained the ability to acetylate histones. Hence, the PHD finger appears to negatively regulate self-acetylation. Furthermore, our data suggest that the PHD finger has a role in the recruitment of p300 to chromatin. PMID:25158095

  16. Rewiring AMPK and Mitochondrial Retrograde Signaling for Metabolic Control of Aging and Histone Acetylation in Respiratory-Defective Cells

    R. Magnus N. Friis

    2014-04-01

    Full Text Available Abnormal respiratory metabolism plays a role in numerous human disorders. We find that regulation of overall histone acetylation is perturbed in respiratory-incompetent (ρ0 yeast. Because histone acetylation is highly sensitive to acetyl-coenzyme A (acetyl-CoA availability, we sought interventions that suppress this ρ0 phenotype through reprogramming metabolism. Nutritional intervention studies led to the discovery that genetic coactivation of the mitochondrion-to-nucleus retrograde (RTG response and the AMPK (Snf1 pathway prevents abnormal histone deacetylation in ρ0 cells. Metabolic profiling of signaling mutants uncovered links between chromatin-dependent phenotypes of ρ0 cells and metabolism of ATP, acetyl-CoA, glutathione, branched-chain amino acids, and the storage carbohydrate trehalose. Importantly, RTG/AMPK activation reprograms energy metabolism to increase the supply of acetyl-CoA to lysine acetyltransferases and extend the chronological lifespan of ρ0 cells. Our results strengthen the framework for rational design of nutrient supplementation schemes and drug-discovery initiatives aimed at mimicking the therapeutic benefits of dietary interventions.

  17. EFFECTS OF CURCUMIN ON PROLIFERATION OF NB4 CELLS AND ACETYLATION OF HISTONE H3 AND P53

    陈燕; 李新刚; 吴青

    2004-01-01

    Objective: To investigate the effects of curcumin on the proliferation of NB4 cells and the acetylation of histone H3 and no-histone p53. Methods: NB4 cells were cultured and treated with or without curcumin at different concentration (50 (mol/L, 25(mol/L, 12.5(mol/L, 6.25(mol/L, 3.125(mol/L) at various time points (oh, 4h, 8h, 12h, 24h). Western blot analysis was performed to determine the level of acetylated histone H3, p53 and acetylated p53, MTT assay was performed to examine the proliferation of NB4 cells. Results: the proliferation of NB4 cells was inhibited by curcumin in a time- and dose-dependent manner, the IC50 at 24h and 36h were 40(mol/L and 25(mol/L respectively. The levels of acetylated histone H3 and acetylated p53 were increased obviously. Conclusion: curcumin possessed the founction of deacetylases inhibitor, increased the level of acetylated histone H3 and the expression of tumor suppressor p53, enhanced later's activity, and inhibited the proliferation of NB4 cell.

  18. Accurate in silico identification of species-specific acetylation sites by integrating protein sequence-derived and functional features

    Li, Yuan; Wang, Mingjun; Wang, Huilin; Tan, Hao; Zhang, Ziding; Webb, Geoffrey I.; Song, Jiangning

    2014-07-01

    Lysine acetylation is a reversible post-translational modification, playing an important role in cytokine signaling, transcriptional regulation, and apoptosis. To fully understand acetylation mechanisms, identification of substrates and specific acetylation sites is crucial. Experimental identification is often time-consuming and expensive. Alternative bioinformatics methods are cost-effective and can be used in a high-throughput manner to generate relatively precise predictions. Here we develop a method termed as SSPKA for species-specific lysine acetylation prediction, using random forest classifiers that combine sequence-derived and functional features with two-step feature selection. Feature importance analysis indicates functional features, applied for lysine acetylation site prediction for the first time, significantly improve the predictive performance. We apply the SSPKA model to screen the entire human proteome and identify many high-confidence putative substrates that are not previously identified. The results along with the implemented Java tool, serve as useful resources to elucidate the mechanism of lysine acetylation and facilitate hypothesis-driven experimental design and validation.

  19. What a Role did Histidine Residue Play in Arylamine N-Acetyltransferase 2 Acetylation? A Quantum Chemistry Study

    QIAO Qing-An; CAI Zheng-Ting; YANG Chuan-Lu; WANG Mei-Shan

    2006-01-01

    Arylamine N-acetyltransferases (NATs, EC 2.3.1.5) catalyze an acetyl group transfer from acetyl coenzyme A (AcCoA) to primary arylamines and play a very important role in the metabolism and bioactivation of drugs and carcinogens. Experiments revealed that His-107 was likely the residues responsible for mediating acetyl transfer.The full catalytic mechanism of acetylation process has been examined by density functional theory. The results indicate that, if the acetyl group is directly transferred from the donor, p-nitrophenyl acetate, to the acceptor, cysteine,the high activation energy will be a great hindrance. These energies have dropped in a little range of 20-25 k J/mol when His-107 assisted the transfer process. However, when protonated His-107 mediated the reaction, the activation energies have been dropped about 73-85 kJ/mol. Our calculations strongly supported an enzyme acetylation mechanism that experiences a thiolate-imidazolium pair, and verified the presumption from experiments.

  20. Interactions between N-acetyl-L-cysteine protected CdTe quantum dots and doxorubicin through spectroscopic method

    Highlights: • CdTe quantum dots with the diameter of 3–5 nm were synthesized in aqueous solution. • The modified CdTe quantum dots showed well fluorescence properties. • The interaction between the CdTe quantum dots and doxorubicin (DR) was investigated. - Abstract: N-acetyl-L-cysteine protected cadmium telluride quantum dots with a diameter of 3–5 nm were synthesized in aqueous solution. The interaction between N-acetyl-L-cysteine/cadmium telluride quantum dots and doxorubicin was investigated by ultraviolet–visible absorption and fluorescence spectroscopy at physiological conditions (pH 7.2, 37 °C). The results indicate that electron transfer has occurred between N-acetyl-L-cysteine/cadmium telluride quantum dots and doxorubicin under light illumination. The quantum dots react readily with doxorubicin to form a N-acetyl-L-cysteine/cadmium telluride-quantum dots/doxorubicin complex via electrostatic attraction between the −NH3+ moiety of doxorubicin and the −COO− moiety of N-acetyl-L-cysteine/cadmium telluride quantum dots. The interaction of N-acetyl-L-cysteine/cadmium telluride-quantum dots/doxorubicin complex with bovine serum albumin was studied as well, showing that the complex might induce the conformation change of bovine serum due to changes in microenvironment of bovine serum

  1. Synthesis and characterization of bionanocomposites with tunable properties from poly(lactic acid) and acetylated microfibrillated cellulose.

    Tingaut, Philippe; Zimmermann, Tanja; Lopez-Suevos, Francisco

    2010-02-01

    In the present study, novel bionanocomposite materials with tunable properties were successfully prepared using a poly(lactic acid) (PLA) matrix and acetylated microfibrillated cellulose (MFC) as reinforcing agent. The acetylation of MFC was confirmed by FTIR and (13)C CP-MAS NMR spectroscopies. The grafting of acetyl moieties on the cellulose surface not only prevented MFC hornification upon drying but also dramatically improved redispersibility of the powdered nanofibers in chloroform, a PLA solvent of low polarity. Moreover, we demonstrate that the properties of the resulting PLA nanocomposites could be tailored by adjusting both the acetyl content (Ac%) and the amount of MFC. These nanomaterials showed improved filler dispersion, higher thermal stability, and reduced hygroscopicity with respect to those prepared with unmodified MFC. Dynamic mechanical analysis (DMA) highlighted the reinforcing potential of both the unmodified and the acetylated MFC on the viscoelastic properties of the neat PLA. But more interesting, an increase in the PLA glass transition temperature was detected when using the 8.5% acetylated MFC at 17 wt %, indicating an improved compatibility at the fiber-matrix interface. These findings suggest that the final properties of nanocomposite materials can be controlled by adjusting the %Ac of MFC. PMID:20025270

  2. Sources, Sinks and Cycling of Acetyl Radicals in Tobacco Smoke: A Model for Biomass Burning Chemistry

    Hu, N.; Green, S. A.

    2012-12-01

    Smoke near the source of biomass burning contains high concentrations of reactive compounds, with NO and CH3CHO concentrations four to six orders of magnitude higher than those in the ambient atmosphere. Tobacco smoke represents a special case of biomass burning that is quite reproducible in the lab and may elucidate early processes in smoke from other sources. The origins, identities, and reactions of radical species in tobacco smoke are not well understood, despite decades of study on the concentrations and toxicities of the relatively stable compounds in smoke. We propose that reactions of NO2 and aldehydes are a primary source for transient free radicals in tobacco smoke, which contrasts with the long-surmised mechanism of reaction between NO2 and dienes. The objective of this study was to investigate the sources, sinks and cycling of acetyl radical in tobacco smoke. Experimentally, the production of acetyl radical was demonstrated both in tobacco smoke and in a simplified mixture of air combined with NO and acetaldehyde, both of which are significant components of smoke. Acetyl radicals were trapped from the gas phase using 3-amino-2, 2, 5, 5-tetramethyl-proxyl (3AP) on solid support to form stable 3AP adducts for later analysis by high performance liquid chromatography (HPLC), mass spectrometry/tandem mass spectrometry (MS-MS/MS) and liquid chromatography-mass spectrometry (LC-MS). The dynamic nature of radical cycling in smoke makes it impossible to define a fixed concentration of radical species; 2.15×e13-3.18×e14 molecules/cm3 of acetyl radicals were measured from different cigarette samples and smoking conditions. Matlab was employed to simulate reactions of NO, NO2, O2, and a simplified set of organic compounds known to be present in smoke, with a special emphasis on acetaldehyde and the acetyl radical. The NO2/acetaldehyde mechanism initiates a cascade of chain reactions, which accounts for the most prevalent known carbon-centered radicals found in

  3. N-acetylation and phosphorylation of Sec complex subunits in the ER membrane

    Soromani Christina

    2012-12-01

    Full Text Available Abstract Background Covalent modifications of proteins provide a mechanism to control protein function. Here, we have investigated modifications of the heptameric Sec complex which is responsible for post-translational protein import into the endoplasmic reticulum (ER. It consists of the Sec61 complex (Sec61p, Sbh1p, Sss1p which on its own mediates cotranslational protein import into the ER and the Sec63 complex (Sec63p, Sec62p, Sec71p, Sec72p. Little is known about the biogenesis and regulation of individual Sec complex subunits. Results We show that Sbh1p when it is part of the Sec61 complex is phosphorylated on T5 which is flanked by proline residues. The phosphorylation site is conserved in mammalian Sec61ß, but only partially in birds, and not in other vertebrates or unicellular eukaryotes, suggesting convergent evolution. Mutation of T5 to A did not affect the ability of mutant Sbh1p to complement the growth defect in a Δsbh1Δsbh2 strain, and did not result in a hypophosphorylated protein which shows that alternate sites can be used by the T5 kinase. A survey of yeast phosphoproteome data shows that Sbh1p can be phosphorylated on multiple sites which are organized in two patches, one at the N-terminus of its cytosolic domain, the other proximal to the transmembrane domain. Surprisingly, although N-acetylation has been shown to interfere with ER targeting, we found that both Sbh1p and Sec62p are cotranslationally N-acetylated by NatA, and N-acetyl-proteome data indicate that Sec61p is modified by the same enzyme. Mutation of the N-acetylation site, however, did not affect Sec62p function in posttranslational protein import into the ER. Disabling NatA resulted in growth retardation, but not in co- or posttranslational translocation defects or instability of Sec62p or Sbh1p. Conclusions We conclude that N-acetylation of transmembrane and tail-anchored proteins does not interfere with their ER-targeting, and that Sbh1p phosphorylation on T5

  4. Identification and analysis of the acetylated status of poplar proteins reveals analogous N-terminal protein processing mechanisms with other eukaryotes.

    Chang-Cai Liu

    Full Text Available BACKGROUND: The N-terminal protein processing mechanism (NPM including N-terminal Met excision (NME and N-terminal acetylation (N(α-acetylation represents a common protein co-translational process of some eukaryotes. However, this NPM occurred in woody plants yet remains unknown. METHODOLOGY/PRINCIPAL FINDINGS: To reveal the NPM in poplar, we investigated the N(α-acetylation status of poplar proteins during dormancy by combining tandem mass spectrometry with TiO2 enrichment of acetylated peptides. We identified 58 N-terminally acetylated (N(α-acetylated proteins. Most proteins (47, >81% are subjected to N(α-acetylation following the N-terminal removal of Met, indicating that N(α-acetylation and NME represent a common NPM of poplar proteins. Furthermore, we confirm that poplar shares the analogous NME and N(α-acetylation (NPM to other eukaryotes according to analysis of N-terminal features of these acetylated proteins combined with genome-wide identification of the involving methionine aminopeptidases (MAPs and N-terminal acetyltransferase (Nat enzymes in poplar. The N(α-acetylated reactions and the involving enzymes of these poplar proteins are also identified based on those of yeast and human, as well as the subcellular location information of these poplar proteins. CONCLUSIONS/SIGNIFICANCE: This study represents the first extensive investigation of N(α-acetylation events in woody plants, the results of which will provide useful resources for future unraveling the regulatory mechanisms of N(α-acetylation of proteins in poplar.

  5. N-acetyl-L-leucine accelerates vestibular compensation after unilateral labyrinthectomy by action in the cerebellum and thalamus.

    Günther, Lisa; Beck, Roswitha; Xiong, Guoming; Potschka, Heidrun; Jahn, Klaus; Bartenstein, Peter; Brandt, Thomas; Dutia, Mayank; Dieterich, Marianne; Strupp, Michael; la Fougère, Christian; Zwergal, Andreas

    2015-01-01

    An acute unilateral vestibular lesion leads to a vestibular tone imbalance with nystagmus, head roll tilt and postural imbalance. These deficits gradually decrease over days to weeks due to central vestibular compensation (VC). This study investigated the effects of i.v. N-acetyl-DL-leucine, N-acetyl-L-leucine and N-acetyl-D-leucine on VC using behavioural testing and serial [18F]-Fluoro-desoxyglucose ([18F]-FDG)-μPET in a rat model of unilateral chemical labyrinthectomy (UL). Vestibular behavioural testing included measurements of nystagmus, head roll tilt and postural imbalance as well as sequential whole-brain [18F]-FDG-μPET was done before and on days 1,3,7 and 15 after UL. A significant reduction of postural imbalance scores was identified on day 7 in the N-acetyl-DL-leucine (p D-leucine group (comparison for applied dose of 24 mg i.v. per rat, equivalent to 60 mg/kg body weight, in each group). The course of postural compensation in the DL- and L-group was accelerated by about 6 days relative to controls. The effect of N-acetyl-L-leucine on postural compensation depended on the dose: in contrast to 60 mg/kg, doses of 15 mg/kg and 3.75 mg/kg had no significant effect. N-acetyl-L-leucine did not change the compensation of nystagmus or head roll tilt at any dose. Measurements of the regional cerebral glucose metabolism (rCGM) by means of μPET revealed that only N-acetyl-L-leucine but not N-acetyl-D-leucine caused a significant increase of rCGM in the vestibulocerebellum and a decrease in the posterolateral thalamus and subthalamic region on days 3 and 7. A similar pattern was found when comparing the effect of N-acetyl-L-leucine on rCGM in an UL-group and a sham UL-group without vestibular damage. In conclusion, N-acetyl-L-leucine improves compensation of postural symptoms after UL in a dose-dependent and specific manner, most likely by activating the vestibulocerebellum and deactivating the posterolateral thalamus. PMID:25803613

  6. Acetylation of retinal histones in diabetes increases inflammatory proteins: effects of minocycline and manipulation of histone acetyltransferase (HAT) and histone deacetylase (HDAC).

    Kadiyala, Chandra Sekhar Rao; Zheng, Ling; Du, Yunpeng; Yohannes, Elizabeth; Kao, Hung-Ying; Miyagi, Masaru; Kern, Timothy S

    2012-07-27

    Histone acetylation was significantly increased in retinas from diabetic rats, and this acetylation was inhibited in diabetics treated with minocycline, a drug known to inhibit early diabetic retinopathy in animals. Histone acetylation and expression of inflammatory proteins that have been implicated in the pathogenesis of diabetic retinopathy were increased likewise in cultured retinal Müller glia grown in a diabetes-like concentration of glucose. Both the acetylation and induction of the inflammatory proteins in elevated glucose levels were significantly inhibited by inhibitors of histone acetyltransferase (garcinol and antisense against the histone acetylase, p300) or activators of histone deacetylase (theophylline and resveratrol) and were increased by the histone deacetylase inhibitor, suberolylanilide hydroxamic acid. We conclude that hyperglycemia causes acetylation of retinal histones (and probably other proteins) and that the acetylation contributes to the hyperglycemia-induced up-regulation of proinflammatory proteins and thereby to the development of diabetic retinopathy. PMID:22648458

  7. Structure Elucidation of New Acetylated Saponins, Lessoniosides A, B, C, D, and E, and Non-Acetylated Saponins, Lessoniosides F and G, from the Viscera of the Sea Cucumber Holothuria lessoni

    Yadollah Bahrami

    2015-01-01

    Full Text Available Sea cucumbers produce numerous compounds with a wide range of chemical structural diversity. Among these, saponins are the most diverse and include sulfated, non-sulfated, acetylated and methylated congeners with different aglycone and sugar moieties. In this study, MALDI and ESI tandem mass spectrometry, in the positive ion mode, were used to elucidate the structure of new saponins extracted from the viscera of H. lessoni. Fragmentation of the aglycone provided structural information on the presence of the acetyl group. The presence of the O-acetyl group was confirmed by observing the mass transition of 60 u corresponding to the loss of a molecule of acetic acid. Ion fingerprints from the glycosidic cleavage provided information on the mass of the aglycone (core, and the sequence and type of monosaccharides that constitute the sugar moiety. The tandem mass spectra of the saponin precursor ions [M + Na]+ provided a wealth of detailed structural information on the glycosidic bond cleavages. As a result, and in conjunction with existing literature, we characterized the structure of five new acetylated saponins, Lessoniosides A–E, along with two non-acetylated saponins Lessoniosides F and G at m/z 1477.7, which are promising candidates for future drug development. The presented strategy allows a rapid, reliable and complete analysis of native saponins.

  8. Acetyl-L-carnitine improves behavior and dendritic morphology in a mouse model of Rett syndrome.

    Laura R Schaevitz

    Full Text Available Rett syndrome (RTT is a devastating neurodevelopmental disorder affecting 1 in 10,000 girls. Approximately 90% of cases are caused by spontaneous mutations in the X-linked gene encoding methyl-CpG-binding protein 2 (MeCP2. Girls with RTT suffer from severe motor, respiratory, cognitive and social abnormalities attributed to early deficits in synaptic connectivity which manifest in the adult as a myriad of physiological and anatomical abnormalities including, but not limited to, dimished dendritic complexity. Supplementation with acetyl-L-carnitine (ALC, an acetyl group donor, ameliorates motor and cognitive deficits in other disease models through a variety of mechanisms including altering patterns of histone acetylation resulting in changes in gene expression, and stimulating biosynthetic pathways such as acetylcholine. We hypothesized ALC treatment during critical periods in cortical development would promote normal synaptic maturation, and continuing treatment would improve behavioral deficits in the Mecp2(1lox mouse model of RTT. In this study, wildtype and Mecp2(1lox mutant mice received daily injections of ALC from birth until death (postnatal day 47. General health, motor, respiratory, and cognitive functions were assessed at several time points during symptom progression. ALC improved weight gain, grip strength, activity levels, prevented metabolic abnormalities and modestly improved cognitive function in Mecp2 null mice early in the course of treatment, but did not significantly improve motor or cognitive functions assessed later in life. ALC treatment from birth was associated with an almost complete rescue of hippocampal dendritic morphology abnormalities with no discernable side effects in the mutant mice. Therefore, ALC appears to be a promising therapeutic approach to treating early RTT symptoms and may be useful in combination with other therapies.

  9. Histone acetylation: from code to web and router via intrinsically disordered regions.

    Horikoshi, Masami

    2013-01-01

    Structural changes of chromatin, which consists of nucleosomes and nucleosome-associated factors, lead to functional changes that are important determinants of eukaryotic gene regulation. These structural changes are regulated by modifications of histones and DNA, both of which are components of nucleosomes, as well as by replacement of histone variants and the actions of noncoding RNAs. In studies of chromatin modifications, a great deal of attention has been paid to histone acetylation. Progress in understanding this subject has been extensive, including i) elucidation of the relationship of histone acetylation and gene activity; ii) the first isolation of a histonemodifying enzyme; iii) the first identification of a factor that recognizes a modified site; iv) elucidation of the mechanism by which histone modification leads to structural changes in nucleosomes; and v) elucidation of the mechanism of border formation between euchromatin and heterochromatin. Histone acetylation is considered to be fundamental in several fields, including studies of a) the role of chromatin and epigenetics in higher-order biochemical systems such as transcription, DNA replication, and repair; b) biological phenomena such as cell proliferation and differentiation; and c) cancer and aging, potentially leading to clinical applications. In this review, I will discuss the histone code hypothesis, at one time believed to represent a unified theory regarding the functions of histone modification. In addition, I will describe the "modification web theory, " by which the problems in the histone code hypothesis can be overcome, as well as the "signal router theory, " which explains the mechanisms of formation, development, and evolution of the modification web from a structural viewpoint. Lastly, I will illustrate how these novel theories partially explain the robustness of biological systems against various perturbations, and elucidate the strategy that a cell employs to avoid fatal

  10. Isoniazid acetylating phenotype in patients with paracoccidioidomycosis and its relationship with serum sulfadoxin levels, glucose-6-phosphate dehydrogenase and glutathione reductase activities

    Benedito Barraviera; Paulo Câmara Marques Pereira; Jussara Marcondes Machado; Maria Julia de Souza; Carlos Roberto G. Lima; Paulo Roberto Curi; Rinaldo Poncio Mendes; Domingos Alves Meira

    1991-01-01

    The authors evaluated the isoniazid acetylating phenotype and measured hematocrit, hemoglobin, glucose-6-phosphate dehydrogenase and glutathione reductase activities plus serum sulfadoxin levels in 39 patients with paracoccidioidomycosis (33 males and 6 females) aged 17 to 58 years. Twenty one (53.84%) of the patients presented a slow acetylatingphenotype and 18(46.16%) a fast acetylating phenotype. Glucose-6-phosphate- dehydrogenase (G6PD) acti vity was decreased in 5(23.80%) slow acetylator...

  11. Production of Nα-acetylated thymosin α1 in Escherichia coli

    Fang Hongqing; Li Shulong; Dai Hongmei; Yao Xueqin; Ren Yuantao; Chen Huipeng; Zhou Changlin

    2011-01-01

    Abstract Background Thymosin α1 (Tα1), a 28-amino acid Nα-acetylated peptide, has a powerful general immunostimulating activity. Although biosynthesis is an attractive means of large-scale manufacture, to date, Tα1 can only be chemosynthesized because of two obstacles to its biosynthesis: the difficulties in expressing small peptides and obtaining Nα-acetylation. In this study, we describe a novel production process for Nα-acetylated Tα1 in Escherichia coli. Results To obtain recombinant Nα-a...

  12. N-acetyl-4-aminophenol and musculoskeletal adaptations to resistance exercise training

    Jankowski, Catherine M.; Gozansky, Wendolyn S.; MacLean, Paul S.; Shulman, Benjamin; Wolfe, Pamela; Schwartz, Robert S.; Kohrt, Wendy M.

    2012-01-01

    N-acetyl-4-aminophenol (ACET) may impair musculoskeletal adaptations to progressive resistance exercise training (PRT) by inhibiting exercise-induced muscle protein synthesis and bone formation. To test the hypothesis that ACET would diminish training-induced increases in fat-free mass (FFM) and osteogenesis, untrained men (n = 26) aged ≥50 years participated in 16 weeks of high-intensity PRT and bone-loading exercises and were randomly assigned to take ACET (1,000 mg/day) or placebo (PLAC) 2...

  13. N-Acetyl-5-chloro-3-nitro-l-tyrosine ethyl ester

    Teresa T. Mutahi

    2012-09-01

    Full Text Available The title compound, C13H15ClN2O6, was synthesized by hypochlorous acid-mediated chlorination of N-acetyl-3-nitro-l-tyrosine ethyl ester. The OH group forms an intramolecular O—H...O hydrogen bond to the nitro group and the N—H group forms an intermolecular N—H...O hydrogen bonds to an amide O atom, linking the molecules into chains along [100]. The crystal studied was a non-merohedral twin, with a 0.907 (4:0.093 (4 domain ratio.

  14. N-Acetyl glycals are tight-binding and environmentally insensitive inhibitors of hexosaminidases.

    Santana, A G; Vadlamani, G; Mark, B L; Withers, S G

    2016-06-28

    Mono-, di- and trisaccharide derivatives of 1,2-unsaturated N-acetyl-d-glucal have been synthesized and shown to function as tight-binding inhibitors/slow substrates of representative hexosaminidases. Turnover is slow and not observed in the thioamide analogue, allowing determination of the 3-dimensional structure of the complex. Inhibition is insensitive to pH and to mutation of key catalytic residues, consistent with the uncharged character of the inhibitor. These properties could render this inhibitor class less prone to development of resistance. PMID:27253678

  15. 2-acetyl-1-pyrroline - key aroma compound in Mediterranean dried sausages

    Stahnke, Marie Louise Heller

    2000-01-01

    In a study characterising sausage types from various parts of Europe, ten Mediterranean and Northern European fermented, dried sausages were compared using static headspace gas chromatography-olfactometry and a sniffing panel of five members. The greatest difference between the Northern and...... Southern types were attributed to a burned coffee odour from smoke in the smoked sausages and a popcorn note in the Mediterranean products covered with mould. The two compounds were 2-furfurylthiol and 2-acetyl-1-pyrroline, respectively. An analysis of five dried, moulded sausages showed that the surface...

  16. Yeast Enhancer of Polycomb defines global Esa1-dependent acetylation of chromatin

    Boudreault, Alexandre A.; Cronier, Dominique; Selleck, William; Lacoste, Nicolas; Utley, Rhea T.; Allard, Stéphane; Savard, Julie; Lane, William S.; Tan, Song; Côté, Jacques

    2003-01-01

    Drosophila Enhancer of Polycomb, E(Pc), is a suppressor of position-effect variegation and an enhancer of both Polycomb and trithorax mutations. A homologous yeast protein, Epl1, is a subunit of the NuA4 histone acetyltransferase complex. Epl1 depletion causes cells to accumulate in G2/M and global loss of acetylated histones H4 and H2A. In relation to the Drosophila protein, mutation of Epl1 suppresses gene silencing by telomere position effect. Epl1 protein is found ...

  17. Wheat cytosolic acetyl-CoA carboxylase complements an ACC1 null mutation in yeast

    Joachimiak, M.; Tevzadze, G.; Podkowinski, J; Haselkorn, R.; Gornicki, P.

    1997-01-01

    Spores harboring an ACC1 deletion derived from a diploid Saccharomyces cerevisiae strain, in which one copy of the entire ACC1 gene is replaced with a LEU2 cassette, fail to grow. A chimeric gene consisting of the yeast GAL10 promoter, yeast ACC1 leader, wheat cytosolic acetyl-CoA carboxylase (ACCase) cDNA, and yeast ACC1 3′ tail was used to complement a yeast ACC1 mutation. The complementation demonstrates that active wheat ACCase can be produced in yeast. At low concentrations of galactose,...

  18. Ras protein participated in histone acetylation-mediated cell cycle control in Physarum polycephalum

    LI Xiaoxue; LU Jun; ZHAO Yanmei; WANG Xiuli; HUANG Baiqu

    2005-01-01

    In this paper, we demonstrate that in Physarum polycephalum, a naturally synchronized slime mold, histone deacetylase (HDAC) inhibitor Trichostatin A (TSA), arrestes the cell cycle at the checkpoints of S/G2, G2/M and mitosis exit, and influences the transcription of two ras genes Ppras1 and Pprap1, as well as the Ras protein level. Antibody neutralization experiment using anti-Ras antibody treatment showed that Ras protein played an important role in cell cycle checkpoint control through regulation of the level of Cyclin B1, suggesting that Ras protein might be a key factor for histone acetylation-mediated cell cycle regulation in P. polycephalum.

  19. A CXCL8 receptor antagonist based on the structure of N-Acetyl-Proline-Glycine-Proline

    Jackson, Patricia L; Noerager, Brett D.; Jablonsky, Michael J; Hardison, Matthew T.; Cox, Bryan D; Patterson, James C.; Dhanapal, Boopathy; Blalock, J Edwin; Muccio, Donald D

    2011-01-01

    A role for the collagen-derived tripeptide, N-acetyl proline-glycine-proline (NAc-PGP), in neutrophil recruitment in chronic airway inflammatory diseases, including COPD and cystic fibrosis, has recently been delineated. Due to structural similarity to an important motif for interleukin-8 (CXCL8) binding to its receptor, NAc-PGP binds to CXCR1/2 receptors, leading to neutrophil activation and chemotaxis. In an effort to develop novel CXCL8 antagonists, we describe the synthesis of four chiral...

  20. Genome-wide reduction in H3K9 acetylation during human embryonic stem cell differentiation

    Krejčí, Jana; Uhlířová, Radka; Galiová-Šustáčková, Gabriela; Kozubek, Stanislav; Šmigová, Jana; Bártová, Eva

    2009-01-01

    Roč. 219, č. 3 (2009), s. 677-687. ISSN 0021-9541 R&D Projects: GA MŠk(CZ) LC06027; GA MŠk(CZ) LC535; GA ČR(CZ) GA204/06/0978 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702; CEZ:AV0Z50110509 Keywords : hESC * H3K9 acetylation * epigenetics Subject RIV: BO - Biophysics Impact factor: 4.586, year: 2009

  1. BRPF3-HBO1 regulates replication origin activation and histone H3K14 acetylation

    Feng, Yunpeng; Vlassis, Arsenios; Roques, Céline;

    2016-01-01

    During DNA replication, thousands of replication origins are activated across the genome. Chromatin architecture contributes to origin specification and usage, yet it remains unclear which chromatin features impact on DNA replication. Here, we perform a RNAi screen for chromatin regulators......45 recruitment, but not MCM2-7 loading, is impaired in BRPF3-depleted cells, identifying a BRPF3-dependent function of HBO1 in origin activation that is complementary to its role in licencing. We thus propose that BRPF3-HBO1 acetylation of histone H3K14 around TSS facilitates efficient activation of...

  2. A conformational study of N -acetyl glucosamine derivatives utilizing residual dipolar couplings

    Kramer, Markus; Kleinpeter, Erich

    2011-09-01

    The conformational analyses of six non-rigid N-acetyl glucosamine (NAG) derivatives employing residual dipolar couplings (RDCs) and NOEs together with molecular dynamics (MD) simulations are presented. Due to internal dynamics we had to consider different conformer ratios existing in solution. The good quality of the correlation between theoretically and experimentally obtained RDCs show the correctness of the calculated conformers even if the ratios derived from the MD simulations do not exactly meet the experimental data. If possible, the results were compared to former published data and commented.

  3. Characterisation of N-acetyl-D-glucosamine (NAG) as a lyoluminescent dosemeter

    Lyoluminescent properties of N-acetyl-D-glucosamine (NAG) were investigated for their suitability as a dosemeter in a lyoluminescent system using sensitised solutions as solvents. Temperature and pH of the solvents were also varied. The detection limit for the system NAG-luminol at 200C using a solvent pH value of 10.6 was of the order of 3 mGy. The reproducibility was within ± 5% for doses of the order of 1 Gy. Measurements with isoluminol showed slightly higher amplification of the LL signal than that obtained with luminol. (author)

  4. Cell differentiation along multiple pathways accompanied by changes in histone acetylation status

    Legartová, Soňa; Kozubek, Stanislav; Franěk, Michal; Zdráhal, Z.; Lochmanová, G.; Martinet, N.; Bártová, Eva

    2014-01-01

    Roč. 92, č. 2 (2014), s. 85-93. ISSN 0829-8211 R&D Projects: GA ČR(CZ) GAP302/10/1022; GA ČR(CZ) GBP302/12/G157; GA ČR(CZ) GA13-07822S; GA MŠk(CZ) LD11020; GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081707 Keywords : histones * acetylation * epigenetics Subject RIV: BO - Biophysics Impact factor: 2.152, year: 2014

  5. Histone H3 lysine 56 acetylation and the response to DNA replication fork damage

    Wurtele, Hugo; Kaiser, Gitte Schalck; Bacal, Julien;

    2012-01-01

    In Saccharomyces cerevisiae, histone H3 lysine 56 acetylation (H3K56ac) occurs in newly synthesized histones that are deposited throughout the genome during DNA replication. Defects in H3K56ac sensitize cells to genotoxic agents, suggesting that this modification plays an important role in the DNA...... but are only mildly affected by hydroxyurea. We demonstrate that, after exposure to MMS, H3K56ac-deficient cells cannot complete DNA replication and eventually segregate chromosomes with intranuclear foci containing the recombination protein Rad52. In addition, we provide evidence that these...... lesions by recombination and/or from defects in the completion of DNA replication....

  6. Structure and thermotropic properties of 1-stearoyl-2-acetyl-phosphatidylcholine bilayer membranes.

    Shah, J; Duclos, R I; Shipley, G G

    1994-01-01

    The structural and thermotropic properties of 1-stearoyl-2-acetyl-phosphatidylcholine (C(18):C(2)-PC) were studied as a function of hydration. A combination of differential scanning calorimetry and x-ray diffraction techniques have been used to investigate the phase behavior of C(18):C(2)-PC. At low hydration (e.g., 20% H2O), the differential scanning calorimetry heating curve shows a single reversible endothermic transition at 44.6 degrees C with transition enthalpy delta H = 6.4 kcal/mol. T...

  7. Lack of genotoxic potential of acetylated monoglyceride: An alternative plasticiser to phthalates

    Mortensen, Alicja; Wedebye, Eva Bay; Niemelä, Jay Russell;

    2011-01-01

    interest in alternatives. Biodegradable plasticisers produced from sustainable materials, of low toxicity and no endocrine activity offer desirable alternatives to phthalates. The aim of the project was to screen an alternative plasticiser acetoxylated monoglyceride for genotoxic potential. Methods: The...... ability of acetylated monoglyceride to induce genotoxicity in vitro was investigated in silico by QSAR modelling. The first step was to assure that an obtained prediction falls within the applicability domain of the models – that there was sufficient similarity (in relevant descriptors) between the query...

  8. MRG15 activates the cdc2 promoter via histone acetylation in human cells

    Chromatin remodeling is required for transcriptional activation and repression. MRG15 (MORF4L1), a chromatin modulator, is a highly conserved protein and is present in complexes containing histone acetyltransferases (HATs) as well as histone deacetylases (HDACs). Loss of expression of MRG15 in mice and Drosophila results in embryonic lethality and fibroblast and neural stem/progenitor cells cultured from Mrg15 null mouse embryos exhibit marked proliferative defects when compared with wild type cells. To determine the role of MRG15 in cell cycle progression we performed chromatin immunoprecipitation with an antibody to MRG15 on normal human fibroblasts as they entered the cell cycle from a quiescent state, and analyzed various cell cycle gene promoters. The results demonstrated a 3-fold increase in MRG15 occupancy at the cdc2 promoter during S phase of the cell cycle and a concomitant increase in acetylated histone H4. H4 lysine 12 was acetylated at 24 h post-serum stimulation while there was no change in acetylation of lysine 16. HDAC1 and 2 were decreased at this promoter during cell cycle progression. Over-expression of MRG15 in HeLa cells activated a cdc2 promoter-reporter construct in a dose-dependent manner, whereas knockdown of MRG15 resulted in decreased promoter activity. In order to implicate HAT activity, we treated cells with the HAT inhibitor anacardic acid and determined that HAT inhibition results in loss of expression of cdc2 mRNA. Further, chromatin immunoprecipitation with Tip60 localizes the protein to the same 110 bp stretch of the cdc2 promoter pulled down by MRG15. Additionally, we determined that cotransfection of MRG15 with the known associated HAT Tip60 had a cooperative effect in activating the cdc2 promoter. These results suggest that MRG15 is acting in a HAT complex involving Tip60 to modify chromatin via acetylation of histone H4 at the cdc2 promoter to activate transcription.

  9. Acetylation of vitamin E by Candida antarctica lipase B immobilized on different carriers

    Torres, Pamela; Reyes-Duarte, Dolores; López-Cortés, Nieves; Ferrer, Manuel; Ballesteros Olmo, Antonio; Plou Gasca, Francisco José

    2009-01-01

    We describe for the first time the enzymatic acylation of the phenolic group of tocopherols (vitamin E) by transesterification with vinyl acetate in 2-methyl-2-butanol (2M2B). Out of 15 hydrolases screened, only the lipase B from Candida antarctica (Novozym 435) catalyzed the acylation. The acetylation of -tocopherol was faster than that of -tocopherol, probably due to its lower methylation degree. A series of experiments using (R)-Trolox and p-cresol as competitive acceptors of tocopherols...

  10. Influence of different degrees of acetylation in the physical and mechanical properties of particleboards and wood-cement composites

    Setsuo Iwakiri

    2014-12-01

    Full Text Available Chemical modified wood particles used to particleboards manufacture may, at the same time, improve the dimensional stability and damage the internal bond. The aim of this research was find the optimal point of acetylation for particleboards. Pinus taeda particles with different degrees of acetylation, 8, 15 and 20% of weight percentage gain (WGP, were used in the production of particleboards with urea-formaldehyde resin and wood-cement composites produced by mechanical and vibratory compaction. It was evaluated the water absorption, thickness swelling and internal bind of the particleboards according to the European standards EN 317 and EN 319. Particleboards produced with 15 WPG showed the lowest water absorption and thickness swelling values. However, the use of chemically modified wood had a negative influence in the internal bind of the boards. This phenomenon can be explain due to the similar behavior between resin and water, that way, the high degree acetylation stops the adhesive and adherent bind. In the case of wood-cement composites, the internal bind improves as the acetylation degrees get higher. Nevertheless the inhibition of acetylated wood particles to the cement hydration got higher when the WPG was higher than 8%.

  11. Highly Active Copolymerization of Ethylene and N-Acetyl-O-(ω-Alkenyl-l-Tyrosine Ethyl Esters Catalyzed by Titanium Complex

    Jing Wang

    2016-03-01

    Full Text Available A series of N-acetyl-O-(ω-alkenyl-l-tyrosine ethyl esters were synthesized by the reaction of vinyl bromides (4-bromo-1-butene, 6-bromo-1-hexene, 8-bromo-1-octene and 10-bromo-1-decene with N-acetyl-l-tyrosine ethyl ester. 1H NMR, elemental analysis, FT-IR, and mass spectra were performed for these N-acetyl-O-(ω-alkenyl-l-tyrosine ethyl esters. The novel titanium complex can catalyze the copolymerization of ethylene and N-acetyl-O-(ω-alkenyl-l-tyrosine ethyl esters efficiently and the highest catalytic activity was up to 6.86 × 104 gP·(molTi−1·h−1. The structures and properties of the obtained copolymers were characterized by FT-IR, (1H13C NMR, GPC, DSC, and water contact angle. The results indicated that the obtained copolymers had a uniformly high average molecular weight of 2.85 × 105 g·mol−1 and a high incorporation ratio of N-acetyl-O-(but-3-enyl-l-tyrosine ethyl ester of 2.65 mol % within the copolymer chain. The units of the comonomer were isolated within the copolymer chains. The insertion of the polar comonomer into a copolymer chain can effectively improve the hydrophilicity of a copolymer.

  12. [3H]Indole-3-acetyl-myo-inositol hydrolysis by extracts of Zea mays L. vegetative tissue

    [3H]Indole-3-acetyl-myo-inositol was hydrolyzed by buffered extracts of acetone powders prepared from 4 day shoots of dark grown Zea mays L. seedlings. The hydrolytic activity was proportional to the amount of extract added and was linear for up to 6 hours at 370C. Boiled or alcohol denatured extracts were inactive. Analysis of reaction mixtures by high performance liquid chromatography demonstrated that not all isomers of indole-3-acetyl-myo-inositol were hydrolyzed at the same rate. Buffered extracts of acetone powders were prepared from coleoptiles and mesocotyls. The rates of hydrolysis observed with coleoptile extracts were greater than those observed with mesocotyl extracts. Active extracts also catalyzed the hydrolysis of esterase substrates such as α-naphthyl acetate and the methyl esters of indoleacetic acid and naphthyleneacetic acid. Attempts to purify the indole-3-acetyl-myo-inositol hydrolyzing activity by chromatographic procedures resulted in only slight purification with large losses of activity. Chromatography over hydroxylapatite allowed separation of two enzymically active fractions, one of which catalyzed the hydrolysis of both indole-3-acetyl-myo-inositol and esterase substrates. With the other fraction enzymic hydrolysis of esterase substrates was readily demonstrated, but no hydrolysis of indole-3-acetyl-myo-inositol was ever detected

  13. Histone H4 acetylation by immunohistochemistry and prognosis in newly diagnosed adult acute lymphoblastic leukemia (ALL) patients

    Histone deacetylase (HDAC) inhibitors are a novel anti-tumor therapy. To determine whether HDAC inhibitors may be useful in the treatment of adult acute lymphoblastic leukemia (ALL), we examined the acetylation of histone H4 by immunohistochemistry in newly diagnosed ALL patients and evaluated the impact of acetylation on complete remission (CR) rate, relapse-free survival (RFS), and overall survival (OS). Patients ≥18 years of age and an available diagnostic bone marrow biopsy were evaluated. Cox proportional hazards analysis was used to identify univariate and multivariate correlates of CR, RFS, and OS. The variables histone H4 acetylation (positive or negative), white blood count, cytogenetic (CG) risk group (CALGB criteria), and age were used in multivariate analysis. On multivariate analysis, histone acetylation was associated with a trend towards an improved OS (for all CG risk groups) (HR = 0.51, p = 0.09). In patients without poor risk CG, there was an impressive association between the presence of histone acetylation and an improved CR rate (OR 3.43, p = 0.035), RFS (HR 0.07, p = 0.005), and OS (HR 0.24, p = 0.007). This association remained statistically significant in multivariate analysis. These data provide a rationale for the design of novel regimens incorporating HDAC inhibitors in ALL

  14. Histone acetylation influences the transcriptional activation of POX in Beta vulgaris L. and Beta maritima L. under salt stress.

    Yolcu, Seher; Ozdemir, Filiz; Güler, Aybüke; Bor, Melike

    2016-03-01

    Acetylation of histone proteins is a type of chromatin modification which facilitates the activation of genes. Recent studies brought up the importance of this reversible and rapid process for the regulation of gene expression especially in plant defense against a variety of environmental stresses. Deciphering the exact mechanisms of chromatin modifications under abiotic stress conditions is important for improving crop plants' performance and yield. In a previous study we compared the salt stress responses of Beta vulgaris (sugar beet) and Beta maritima (wild beet). In accordance with those results we suggested that chromatin remodeling can be an active process in the regulation of genes related to salt stress tolerance of these plants. Therefore we performed ChIP assay in control and salt stressed (250 and 500 mM NaCl) plants and compared the enrichment of acetylation in the associated chromatin sites. We found that the transcriptional activation of one peroxidase (POX) encoding gene was associated with the elevated levels of acetylation in H3K9 and H3K27 sites. The acetylation patterns were remarkably different between two species in which the highest acetylation levels were found at H3K9 and H3K27 in wild beet and sugar beet respectively. PMID:26773543

  15. [3H]Indole-3-acetyl-myo-inositol hydrolysis by extracts of Zea mays L. vegetative tissue

    Hall, P. J.; Bandurski, R. S.

    1986-01-01

    [3H]Indole-3-acetyl-myo-inositol was hydrolyzed by buffered extracts of acetone powders prepared from 4 day shoots of dark grown Zea mays L. seedlings. The hydrolytic activity was proportional to the amount of extract added and was linear for up to 6 hours at 37 degrees C. Boiled or alcohol denatured extracts were inactive. Analysis of reaction mixtures by high performance liquid chromatography demonstrated that not all isomers of indole-3-acetyl-myo-inositol were hydrolyzed at the same rate. Buffered extracts of acetone powders were prepared from coleoptiles and mesocotyls. The rates of hydrolysis observed with coleoptile extracts were greater than those observed with mesocotyl extracts. Active extracts also catalyzed the hydrolysis of esterase substrates such as alpha-naphthyl acetate and the methyl esters of indoleacetic acid and naphthyleneacetic acid. Attempts to purify the indole-3-acetyl-myo-inositol hydrolyzing activity by chromatographic procedures resulted in only slight purification with large losses of activity. Chromatography over hydroxylapatite allowed separation of two enzymically active fractions, one of which catalyzed the hydrolysis of both indole-3-acetyl-myo-inositol and esterase substrates. With the other enzymic hydrolysis of esterase substrates was readily demonstrated, but no hydrolysis of indole-3-acetyl-myo-inositol was ever detected.

  16. Acetylation of alcohols and phenols under solvent-free conditions using copper zirconium phosphate

    Abdol R. Hajipour; Hirbod Karimi

    2014-01-01

    Copper zirconium phosphate nanoparticles have been used as an efficient catalyst for the acetyla‐tion of a wide range of alcohols and phenols with acetic anhydride in good to excellent yields under solvent‐free conditions. The steric and electronic properties of the different substrates had a signif‐icant influence on the reaction conditions required to achieve the acetylation. The catalyst used in the current study was characterized by inductively‐coupled plasma optical emission spectroscopy, energy dispersive spectroscopy, X‐ray diffraction, N2 adsorption‐desorption, scanning electron microscopy, and transmission electron microscopy. These analyses revealed that the interlayer distance in the catalyst increased from 7.5 to 8.0 Å when Cu2+was intercalated between the layers, whereas the crystallinity of the material was reduced. This nanocatalyst could also be recovered and reused at least six times without any discernible decrease in its catalytic activity. This new method for the acetylation of alcohols and phenols has several key advantages, including mild and environmentally friendly reaction conditions, as well as good to excellent yields and a facile work‐up.

  17. Citrullination-acetylation interplay guides E2F-1 activity during the inflammatory response.

    Ghari, Fatemeh; Quirke, Anne-Marie; Munro, Shonagh; Kawalkowska, Joanna; Picaud, Sarah; McGouran, Joanna; Subramanian, Venkataraman; Muth, Aaron; Williams, Richard; Kessler, Benedikt; Thompson, Paul R; Fillipakopoulos, Panagis; Knapp, Stefan; Venables, Patrick J; La Thangue, Nicholas B

    2016-02-01

    Peptidyl arginine deiminase 4 (PAD4) is a nuclear enzyme that converts arginine residues to citrulline. Although increasingly implicated in inflammatory disease and cancer, the mechanism of action of PAD4 and its functionally relevant pathways remains unclear. E2F transcription factors are a family of master regulators that coordinate gene expression during cellular proliferation and diverse cell fates. We show that E2F-1 is citrullinated by PAD4 in inflammatory cells. Citrullination of E2F-1 assists its chromatin association, specifically to cytokine genes in granulocyte cells. Mechanistically, citrullination augments binding of the BET (bromodomain and extra-terminal domain) family bromodomain reader BRD4 (bromodomain-containing protein 4) to an acetylated domain in E2F-1, and PAD4 and BRD4 coexist with E2F-1 on cytokine gene promoters. Accordingly, the combined inhibition of PAD4 and BRD4 disrupts the chromatin-bound complex and suppresses cytokine gene expression. In the murine collagen-induced arthritis model, chromatin-bound E2F-1 in inflammatory cells and consequent cytokine expression are diminished upon small-molecule inhibition of PAD4 and BRD4, and the combined treatment is clinically efficacious in preventing disease progression. Our results shed light on a new transcription-based mechanism that mediates the inflammatory effect of PAD4 and establish the interplay between citrullination and acetylation in the control of E2F-1 as a regulatory interface for driving inflammatory gene expression. PMID:26989780

  18. Entamoeba histolytica acetyl-CoA synthetase:biomarker of acute amoebic liver abscess

    Lim Boon Huat; Pim Chau Dam; Alfonso Olivos Garcia; Tan Zi Ning; Wong Weng Kin; Rahmah Noordin; Siti Shafiqah Anaqi Azham; Lee Zhi Jie; Guee Cher Ching; Foo Phiaw Chong

    2014-01-01

    Objective: To characterize the Entamoeba histolytica (E. histolytica) antigen(s) recognized by moribound amoebic liver abscess hamsters.Methods:in 1D- and 2D-Western blot analyses. The antigenic protein was then sent for tandem mass spectrometry analysis. The corresponding gene was cloned and expressed in Escherichia coli BL21-AI to produce the recombinant E. histolytica ADP-forming acetyl-CoA synthetase (EhACS) protein. A customised ELISA was developed to evaluate the sensitivity and specificity of the recombinant protein.Results:Crude soluble antigen of E. histolytica was probed with sera of moribund hamsters detected by sera of hamsters in the control group. Tandem mass spectrometry analysis revealed the protein to be the 77 kDa E. histolytica ADP-forming acetyl-CoA synthetase (EhACS). The customised ELISA results revealed 100% sensitivity and 100% specificity when tested against infected (n=31) and control group hamsters (n=5) serum samples, respectively.Conclusions:This finding suggested the significant role of EhACS as a biomarker for moribund A ~75 kDa protein band with a pI value of 5.91-6.5 was found to be antigenic; and not hamsters with acute amoebic liver abscess (ALA) infection. It is deemed pertinent that future studies explore the potential roles of EhACS in better understanding the pathogenesis of ALA; and in the development of vaccine and diagnostic tests to control ALA in human populations.

  19. [Separation and properties of N-acetyl-beta-D-glucosaminidase from human seminal plasma].

    Yoshida, K; Uchijima, Y; Kobayashi, N; Saitoh, H

    1989-11-01

    N-acetyl-beta-D-glucosaminidase from human seminal plasma has been separated by the cellulose acetate electrophoresis into two components, isoenzyme I and II. The two isoenzymes are readily separated on a DEAE-Sephadex column. Isoenzyme I which has adsorbed to the column, is eluted at 0.1 M NaCl, whereas isoenzyme II has passed through the column. The following enzyme properties have been obtained: 1) Both isoenzymes show the same Km values (0.27 X 10(-3) M) towards sodio-m-cresol-sufonphtaleinyl-N-acetyl-beta-D-glucosaminide . 2) Both isoenzymes show the same pH optima of 5.4. 3) Optimal temperature for isoenzyme I is 50 degrees C, while that for isoenzyme II is 65 degrees C. Isoenzyme II is heat stable, while isoenzyme I is easily denatured by heat. These characteristics of isoenzyme I and II coincide with previous reports of NAG A and B from the spleen and the kidney, respectively. The activity ratio of isoenzyme I and II has been studied for the reproductive tissues. The % ratio of isoenzyme I and II in the epididymal head is 62 and 38, that in the epididymal tail is 42 and 58, and 38:62 in the seminal vesicle, 35:65 in the prostatic gland and 27:73 in the seminal plasma. PMID:2593437

  20. An efficient acetylation of dextran using in situ activated acetic anhydride with iodine

    MUHAMMAD A. HUSSAIN

    2010-02-01

    Full Text Available A facile, efficient, cost-effective and solvent-free acetylation method has been developed for the acetylation of dextran. Dextran acetates were successfully synthesized using different molar ratios of acetic anhydride in the presence of iodine as a catalyst without the use of any solvent. The reactions were realized at 50 °C for 3 h under stirring and nitrogen. This efficient method yielded highly pure and organosoluble dextran esters. The reaction appears highly effective for obtaining higher degrees of substitution (DS with great efficiency. Under solvent-free conditions, dextran triacetates were efficiently synthesized. It was also observed that the molar ratio can easily control the DS of pendant groups onto the polymer backbone. Hence, a range of products with varying DS were successfully designed, purified and characterized. Covalent attachment of the pendant groups onto the polymer backbone was verified by spectroscopic techniques. Thermogravimetric analysis indicated that the obtained dextran esters were thermally as stable as dextran. The DS of the pendant groups onto the polymer backbone was calculated using standard acid base titration after saponification. Furthermore, all products were thoroughly characterized by thermal analysis (TG and DTG, and FTIR and 1H-NMR spectroscopic analysis.

  1. New polygalacturonases from Trichoderma reesei: characterization and their specificities to partially methylated and acetylated pectins.

    Mohamed, Saleh A; Christensen, Tove M I E; Mikkelsen, Jorn Dalgaard

    2003-03-14

    Two extracellular isoenzymes of polygalacturonases PG1 and PG2 were isolated from 3-day-old culture filtrates of Trichoderma reesei. The two enzymes were purified to homogeneity by ion-exchange, gel filtration and hydrophobic interaction chromatographies. PG1 and PG2 exhibit similar molecular weights from gel filtration and SDS-PAGE. Their properties, including optimal pH and temperature, thermal stability and Km were compared. Characterization of substrate specificity showed that the two enzymes had higher affinity toward PGA (B0100) derived from sugar beet pectin (SBP) than PGA from lime pectin. A series of SBPs with different distribution patterns of methyl and acetyl groups, produced by treatment with either plant pectin methylesterase (P-series) or fungal pectin methylesterase (F-series) or base catalysis (B-series), was used as substrates for PG1 and PG2. Substrates with a low degree of esterification were preferred substrates. The activities of PG1 and PG2 were strongly correlated to the degree of methylation and very little effect from acetylation. The products generated by digestion of selected lime and SBPs were analysed using matrix assisted laser desorption ionisation time of flight (MALDI TOF) MS. A mode of action revealed a random cleavage pattern for PG1 and PG2, confirming that these enzymes are endopolygalacturonases. PMID:12668107

  2. Ecotoxicity evaluation and removal of sulfonamides and their acetylated metabolites during conventional wastewater treatment.

    García-Galán, María Jesús; González Blanco, Susana; López Roldán, Ramón; Díaz-Cruz, Silvia; Barceló, Damiá

    2012-10-15

    The present study describes the evaluation of the risk posed by the occurrence of sulfonamides (SAs) in wastewaters. A fully automated analytical method based on on-line solid-phase extraction-liquid chromatography-tandem mass spectrometry (on line SPE-LC-MS/MS) was developed, validated and applied for the analysis of sixteen SAs and, for the first time in wastewaters and sewage sludge, five of their acetylated metabolites. Influent and effluent samples from twenty two different wastewater treatment plants (WWTPs) in Catalonia (Spain) and sewage sludge from fifteen of them were analyzed; removal rates (RE%) and half-lives (t(1/2)) for each SA were calculated. The estimated correlations between RE% and to the hydraulic retention time (HRT) of the different plants indicated no clear influence of HRT on removals. Sulfamethoxazole (SMX), sulfapyridine (SPY) and their corresponding acetylated metabolites were detected with the highest frequencies of detection and at the highest concentrations. The ecotoxicity of both SPY and AcSPY was evaluated for the first time through bioluminescent inhibition assays, resulting in a higher toxicity being attributed to the metabolite. Finally, the potential environmental risk posed by the levels of SAs detected was evaluated calculating the hazard quotients (HQ) to different non-target aquatic organisms in treated wastewaters. SMX was the only SA posing a risk to algae, with an HQ>10. PMID:22960452

  3. N-acetyl-l-histidine, a Prominent Biomolecule in Brain and Eye of Poikilothermic Vertebrates

    Baslow, Morris H.; Guilfoyle, David N.

    2015-01-01

    N-acetyl-l-histidine (NAH) is a prominent biomolecule in brain, retina and lens of poikilothermic vertebrates. In fish lens, NAH exhibits an unusual compartmentalized metabolism. It is synthesized from l-histidine (His) and acetyl Co-enzyme A. However, NAH cannot be catabolized by lens cells. For its hydrolysis, NAH is exported to ocular fluid where a specific acylase cleaves His which is then actively taken up by lens and re-synthesized into NAH. This energy-dependent cycling suggested a pump mechanism operating at the lens/ocular fluid interface. Additional studies led to the hypothesis that NAH functioned as a molecular water pump (MWP) to maintain a highly dehydrated lens and avoid cataract formation. In this process, each NAH molecule released to ocular fluid down its gradient carries with it 33 molecules of bound water, effectively transporting the water against a water gradient. In ocular fluid the bound water is released for removal from the eye by the action of NAH acylase. In this paper, we demonstrate for the first time the identification of NAH in fish brain using proton magnetic resonance spectroscopy (MRS) and describe recent evidence supporting the NAH MWP hypothesis. Using MRS, we also document a phylogenetic transition in brain metabolism between poikilothermic and homeothermic vertebrates. PMID:25919898

  4. Acetylated Triterpene Glycosides and Their Biological Activity from Holothuroidea Reported in the Past Six Decades.

    Bahrami, Yadollah; Franco, Christopher M M

    2016-01-01

    Sea cucumbers have been valued for many centuries as a tonic and functional food, dietary delicacies and important ingredients of traditional medicine in many Asian countries. An assortment of bioactive compounds has been described in sea cucumbers. The most important and abundant secondary metabolites from sea cucumbers are triterpene glycosides (saponins). Due to the wide range of their potential biological activities, these natural compounds have gained attention and this has led to their emergence as high value compounds with extended application in nutraceutical, cosmeceutical, medicinal and pharmaceutical products. They are characterized by bearing a wide spectrum of structures, such as sulfated, non-sulfated and acetylated glycosides. Over 700 triterpene glycosides have been reported from the Holothuroidea in which more than 145 are decorated with an acetoxy group having 38 different aglycones. The majority of sea cucumber triterpene glycosides are of the holostane type containing a C18 (20) lactone group and either Δ(7(8)) or Δ(9(11)) double bond in their genins. The acetoxy group is mainly connected to the C-16, C-22, C-23 and/or C-25 of their aglycone. Apparently, the presence of an acetoxy group, particularly at C-16 of the aglycone, plays a significant role in the bioactivity; including induction of caspase, apoptosis, cytotoxicity, anticancer, antifungal and antibacterial activities of these compounds. This manuscript highlights the structure of acetylated saponins, their biological activity, and their structure-activity relationships. PMID:27527190

  5. Inhibition of cell cycle progression by penta-acetyl geniposide in rat C6 glioma cells

    Penta-acetyl geniposide, (Ac)5-GP, the acetylated compound of geniposide, is able to inhibit the growth of rat C6 glioma cells in culture and in the bearing rats. Our recent data indicated that the induction of cell apoptosis and cell cycle arrest at G0/gap phase 1 (G1) by (Ac)5-GP might be associated with the induction of p53 and c-Myc, and mediated via the apoptosis-related bcl-2 family proteins. In this report, we further investigated the mechanism involved in the cell cycle arrest induced by (Ac)5-GP in C6 glioma cells. The inhibitory effect of (Ac)5-GP on the cell cycle progression of C6 glioma cells which arrested cells at the G0/G1 phase was associated with a marked decrease in the protein expression of cyclin D1, and an induction in the content of cyclin-dependent kinase (cdk) inhibitor p21 protein. This effect was correlated with the elevation in p53 levels. Further immunoprecipitation studies found that, in response to the treatment, the formation of cyclin D1/cdk 4 complex declined, preventing the phosphorylation of retinoblastoma (Rb) and the subsequent dissociation of Rb/E2F complex. These results illustrated that the apoptotic effect of (Ac)5-GP, arresting cells at the G0/G1 phase, was exerted by inducing the expression of p21 that, in turn, repressed the activity of cyclin D1/cdk 4 and the phosphorylation of Rb

  6. MYST2 acetyltransferase expression and Histone H4 Lysine acetylation are suppressed in AML.

    Sauer, Tim; Arteaga, Maria Francisca; Isken, Fabienne; Rohde, Christian; Hebestreit, Katja; Mikesch, Jan-Henrik; Stelljes, Matthias; Cui, Chunhong; Zhou, Fengbiao; Göllner, Stefanie; Bäumer, Nicole; Köhler, Gabriele; Krug, Utz; Thiede, Christian; Ehninger, Gerhard; Edemir, Bayram; Schlenke, Peter; Berdel, Wolfgang E; Dugas, Martin; Müller-Tidow, Carsten

    2015-09-01

    Chromatin-modifying enzymes are frequently altered in acute myeloid leukemia (AML). In the current study, we identified MYST2, a core histone acetyltransferase, to be suppressed in blast cells from AML patients compared with nonmalignant hematopoietic progenitor cells. Functionally, loss of MYST2 accelerated leukemic growth and colony formation, while forced expression of MYST2 induced H4K5 acetylation (H4K5Ac) and suppressed hematopoietic progenitor cell growth. Consistently, global H4K5Ac levels were frequently decreased in AML blasts. Low levels of H4K5Ac were most prominent in patients with complex karyotype AML and were associated with inferior overall survival in univariate but not multivariate analysis. ChIP-seq experiments in primary AML patients' blasts revealed widespread H4K5Ac deregulation, most prominent at gene promoters. Taken together, MYST2 is a repressed growth suppressor in AML mediating reduced acetylation of histone 4 at residue 5 and is associated with inferior AML patient survival. PMID:26072331

  7. Contractile actin cables induced by Bacillus anthracis lethal toxin depend on the histone acetylation machinery.

    Rolando, Monica; Stefani, Caroline; Doye, Anne; Acosta, Maria I; Visvikis, Orane; Yevick, Hannah G; Buchrieser, Carmen; Mettouchi, Amel; Bassereau, Patricia; Lemichez, Emmanuel

    2015-10-01

    It remains a challenge to decode the molecular basis of the long-term actin cytoskeleton rearrangements that are governed by the reprogramming of gene expression. Bacillus anthracis lethal toxin (LT) inhibits mitogen-activated protein kinase (MAPK) signaling, thereby modulating gene expression, with major consequences for actin cytoskeleton organization and the loss of endothelial barrier function. Using a laser ablation approach, we characterized the contractile and tensile mechanical properties of LT-induced stress fibers. These actin cables resist pulling forces that are transmitted at cell-matrix interfaces and at cell-cell discontinuous adherens junctions. We report that treating the cells with trichostatin A (TSA), a broad range inhibitor of histone deacetylases (HDACs), or with MS-275, which targets HDAC1, 2 and 3, induces stress fibers. LT decreased the cellular levels of HDAC1, 2 and 3 and reduced the global HDAC activity in the nucleus. Both the LT and TSA treatments induced Rnd3 expression, which is required for the LT-mediated induction of actin stress fibers. Furthermore, we reveal that treating the LT-intoxicated cells with garcinol, an inhibitor of histone acetyl-transferases (HATs), disrupts the stress fibers and limits the monolayer barrier dysfunctions. These data demonstrate the importance of modulating the flux of protein acetylation in order to control actin cytoskeleton organization and the endothelial cell monolayer barrier. PMID:26403219

  8. Cloning and characterization of cotton heteromeric acetyl-CoA carboxylase genes

    2007-01-01

    Heteromeric acetyl-coanzyme A(CoA)carboxylese(ACCase)catalyzes the formation of malonyl-CoA from acetyl-CoA.It plays an essential role in fatty acid synthesis in prokaryotes and most of plants.The heteromeric ACCase is composed of four subunits:biotin carboxylase (BC),biotin carboxyl carrier protein (BCCP),and α-and β-subunits of carboxyltransferese(α-andβ-CT).In this study,we cloned five novel genes encoding the subunits of heteromeric ACCese(one BC,BCCP and β-CT,and two α-CTs) from cotton (Gossypium hirsutum cv.zhongmian 35)by RACE-PCR.The deduced amino acid sequence of these cDNAs shares high similarity with other reported heteromeric ACCese subunits.The phylogenetic analysis indicated that the different subunits of heteromeric ACCase were grouped in a similar pattern.Southern blot analysis revealed the milti-copy patterns of these heteromeric ACCase genes in cotton genome.Semi-quantitative RT-PCR demonstrated that heteromeric ACCese genes were constitutively expressed in all of the cotton tissues,but the transcripts accumulated at a relatively low level in roots.To our knowledge,this is the first report about characterization of the heteromeric ACCase genes in cotton.

  9. Mechanistic studies on the conjugation of methyl isocyanate with N-Acetyl-Cysteine in rats

    In order to investigate the utility of selected thiols as scavengers of MIC, we first assessed the chemical stability of SMG, AMCC and SMC by measuring their rates of reaction in vitro with thiorphan. The initial rates of carbamoylation of thiorpan (0.5 mM) by the above conjugates (0.5 mM) in aqeous buffer at pH 7.4 and 37 deg C were 2.51, 0.76 and 8.47 μmol L-1 min-1, repectively, indicating that the mercapturate AMCC was the most stable of the three MIC conjugates. In light of these results, studies were conducted to examine the effect of pretreatment with N-acetyl-L-cysteine (L-NAC; 500 mg kg-1, i.p.) on the urinary elimination of AMCC in rats dosed with MIC (15 mg kg-1, i.p.). In separate experiments, groups of rats were pretreated with either N-acetyl-D-cysteine (D-NAC) or N-trideuteroacetyl-L-cysteine (d3-L-NAC) in order to explore the mechanism by which MIC undergoes conjugation to AMCC in vivo. The results indicated that exogenous NAC effectively enhancess the urinary excretion of MIC in the form of AMCC, and that it does so lagerly by direct conjugation with the isocyanate, rather than via biosynthesis to GSH. (author). 9 refs., 5 figs

  10. Interactions of egg yolk phosphatidylcholine with cholesteryl polyethoxy neoglycolipids containing N-acetyl- D-glucosamine

    Kemoun, Rachida; Gelhausen, Micaèle; Besson, Françoise; Lafont, Dominique; Buchet, René; Boullanger, Paul; Roux, Bernard

    1999-03-01

    Series of neoglycolipids containing cholesteryl and N-acetyl- D-glucosaminyl groups were synthesized with various ethoxy linkers. Their self aggregations and intermolecular interactions, without and with egg yolk phosphatidylcholine (EYPC), were characterized in dry and hydrated states, by using infrared spectroscopy. The neoglycolipids in the dry state formed intermolecular hydrogen bonds between the CO and N-H or O-H groups of N-acetyl- D-glucosamine (GlcNAc). In the presence of EYPC, these intermolecular interactions were broken and new hydrogen bonds, involving the phosphate group of EYPC and N-H or O-H groups of GlcNAc of neoglycolipid, were formed. The presence of water molecules altered these intermolecular hydrogen bonds. The CO groups of EYPC were not affected by the presence of neoglycolipids, either in hydrated or in dry states, indicating that the GlcNAc polar groups interacted mostly with EYPC phosphate residues. The phase transition-temperature of mixtures of EYPC containing either cholesterol or neoglycolipid were similar, indicating that the cholesteryl group of the neoglycolipid interacted in the same manner as cholesterol with hydrocarbon chains of EYPC. Some structural models of molecular interactions of neoglycolipids were discussed in relation with the molecular recognition of wheat germ agglutinin.

  11. Sesquiterpene Lactones from Cynara cornigera: Acetyl Cholinesterase Inhibition and In Silico Ligand Docking.

    Hegazy, Mohamed-Elamir F; Ibrahim, Abeer Y; Mohamed, Tarik A; Shahat, Abdelaaty A; El Halawany, Ali M; Abdel-Azim, Nahla S; Alsaid, Mansour S; Paré, Paul W

    2016-01-01

    Wild artichoke (Cynara cornigera), a thistle-like perennial belonging to the Asteraceae family, is native to the Mediterranean region, northwestern Africa, and the Canary Islands. While the pleasant, albeit bitter, taste of the leaves and flowers is attributed to the sesquiterpene lactones cynaropicrin and cynarin, a comprehensive phytochemical investigation still needs to be reported. In this study seven sesquiterpene lactones were isolated from an aqueous methanol plant extract, including a new halogenated metabolite (1), the naturally isolated compound sibthorpine (2), and five metabolites isolated for the first time from C. cornigera. Structures were established by spectroscopic methods, including HREIMS, (1 )H, (13 )C, DEPT, (1 )H-(1 )H COSY, HMQC, and HMBC-NMR experiments as well as by X-ray analysis. The isolated bioactive nutrients were analyzed for their antioxidant and metal chelating activity. Compound 1 exhibited a potent metal chelating activity as well as a high antioxidant capacity. Moreover, select compounds were effective as acetyl cholinesterase inhibitors presenting the possibility for such compounds to be examined for anti-neurodegenerative activity. A computational pharmacophore elucidation and docking study was performed to estimate the pharmacophoric features and binding conformation of isolated compounds in the acetyl cholinesterase active site. PMID:26441064

  12. Crystal Structure of the N-Acetyltransferase Domain of Human N-Acetyl-L-Glutamate Synthase in Complex with N-Acetyl-L-Glutamate Provides Insights into Its Catalytic and Regulatory Mechanisms

    Zhao, Gengxiang; Jin, Zhongmin; Allewell, Norma M.; Tuchman, Mendel; Shi, Dashuang

    2013-01-01

    N-acetylglutamate synthase (NAGS) catalyzes the conversion of AcCoA and L-glutamate to CoA and N-acetyl-L-glutamate (NAG), an obligate cofactor for carbamyl phosphate synthetase I (CPSI) in the urea cycle. NAGS deficiency results in elevated levels of plasma ammonia which is neurotoxic. We report herein the first crystal structure of human NAGS, that of the catalytic N-acetyltransferase (hNAT) domain with N-acetyl-L-glutamate bound at 2.1 Å resolution. Functional studies indicate that the hNA...

  13. Antimycobacterial activity of two natural alkaloids, vasicine acetate and 2-acetyl benzylamine, isolated from Indian shrub Adhatoda vasica Ness. leaves

    S Ignacimuthu; N Shanmugam

    2010-12-01

    In folk medicine, Adhatoda vasica Ness. (Acanthaceae) is used to treat asthma and cough. The leaves of A.vasica were powdered and extracted with hexane, ethyl acetate and methanol. The hexane extract showed 97% reduction in colony-forming units (CFU) at 100 g/ml. The hexane extract was subjected to column chromatography. Two natural compounds, vasicine acetate and 2-acetyl benzylamine, were isolated from it. They were bioassayed against Mycobacterium tuberculosis. The two compounds showed strong antimycobacterial activity. Vasicine acetate and 2-acetyl benzylamine isolated from hexane extract of A. vasica leaves, significantly inhibited M. tuberculosis and one multi-drug-resistant (MDR) strain and one sensitive strain at 200 and 50 g/ml, respectively. Our study demonstrated that both the compounds, vasicine acetate and 2-acetyl benzylamine, could be evaluated further for developing a drug to control M. tuberculosis.

  14. Reduction of apoptosis through the mitochondrial pathway by the administration of acetyl-L-carnitine to mouse fibroblasts in culture

    It is shown in literature that stress, such as deprivation of trophic factors and hypoxia, induces apoptosis in cultured cells and in tissues. In light of these results, we explored the possibility of protecting cells from programmed death by improving the metabolism of the mitochondrion. To this end, acetyl-L-carnitine was administered at various concentrations under conditions of serum deprivation. The choice of this drug was based on the accepted notion that acetyl-L-carnitine is able to stabilize mitochondrial membranes and to increase the supply of energy to the organelle. The results presented here indicate that the drug protects cells from apoptotic death: this is demonstrated by a lower positivity to the TUNEL reaction and by a strong reduction of the apoptotic DNA ladder in serum-deprived cells. The involvement of the mitochondrial apoptotic pathway was assessed by cytochrome C release and immunoreactivity to caspase 3. Moreover, acetyl-L-carnitine stimulates cell proliferation

  15. Endothelial SIRT1 prevents adverse arterial remodeling by facilitating HERC2-mediated degradation of acetylated LKB1

    Bai, Bo; Man, Andy W C; Yang, Kangmin;

    2016-01-01

    prevention of vascular ageing. Methods and Results-Co-immunoprecipitation assay demonstrated that SIRT1, via its amino-terminus, binds to the DOC domain of HERC2 [HECT and RLD domain containing E3 ubiquitin protein ligase 2], which then ubiquitinates LKB1 in the nuclear compartment of endothelial cells. Site......-directed mutagenesis revealed that acetylation at lysine (K) 64 of LKB1 triggers the formation of SIRT1/HERC2/LKB1 protein complex and subsequent proteasomal degradation. In vitro cellular studies suggested that accumulation of acetylated LKB1 in the nucleus leads to endothelial activation, in turn stimulating the...... proliferation of vascular smooth muscle cells and the production of extracellular matrix proteins. Chromatin immunoprecipitation quantitative PCR confirmed that acetylated LKB1 interacts with and activates TGFβ1 promoter, which is inhibited by SIRT1. Knocking down either SIRT1 or HERC2 results in an increased...

  16. Swimming exercise ameliorates neurocognitive impairment induced by neonatal exposure to isoflurane and enhances hippocampal histone acetylation in mice.

    Zhong, T; Ren, F; Huang, C S; Zou, W Y; Yang, Y; Pan, Y D; Sun, B; Wang, E; Guo, Q L

    2016-03-01

    Isoflurane-induced neurocognitive impairment in the developing rodent brain is well documented, and regular physical exercise has been demonstrated to be a viable intervention for some types of neurocognitive impairment. This study was designed to investigate the potential protective effect of swimming exercise on both neurocognitive impairment caused by repeated neonatal exposure to isoflurane and the underlying molecular mechanism. Mice received 0.75% isoflurane exposures for 4h on postnatal days 7, 8, and 9. From the third month after anesthesia, the mice were subjected to regular swimming exercise for 4weeks, followed by a contextual fear condition (CFC) trial. We found that repeated neonatal exposure to isoflurane reduced freezing behavior during CFC testing and deregulated hippocampal histone H4K12 acetylation. Conversely, mice subjected to regular swimming exercise showed enhanced hippocampal H3K9, H4K5, and H4K12 acetylation levels, increased numbers of c-Fos-positive cells 1h after CFC training, and less isoflurane-induced memory impairment. We also observed increases in histone acetylation and of cAMP-response element-binding protein (CREB)-binding protein (CBP) during the swimming exercise program. The results suggest that neonatal isoflurane exposure-induced memory impairment was associated with dysregulation of H4K12 acetylation, which may lead to less hippocampal activation following learning tasks. Swimming exercise was associated with enhanced hippocampal histone acetylation and CBP expression. Exercise most likely ameliorated isoflurane-induced memory impairment by enhancing hippocampal histone acetylation and activating more neuron cells during memory formation. PMID:26748054

  17. Introduction of a bacterial acetyl-CoA synthesis pathway improves lactic acid production in Saccharomyces cerevisiae.

    Song, Ji-Yoon; Park, Joon-Song; Kang, Chang Duk; Cho, Hwa-Young; Yang, Dongsik; Lee, Seunghyun; Cho, Kwang Myung

    2016-05-01

    Acid-tolerant Saccharomyces cerevisiae was engineered to produce lactic acid by expressing heterologous lactate dehydrogenase (LDH) genes, while attenuating several key pathway genes, including glycerol-3-phosphate dehydrogenase1 (GPD1) and cytochrome-c oxidoreductase2 (CYB2). In order to increase the yield of lactic acid further, the ethanol production pathway was attenuated by disrupting the pyruvate decarboxylase1 (PDC1) and alcohol dehydrogenase1 (ADH1) genes. Despite an increase in lactic acid yield, severe reduction of the growth rate and glucose consumption rate owing to the absence of ADH1 caused a considerable decrease in the overall productivity. In Δadh1 cells, the levels of acetyl-CoA, a key precursor for biologically applicable components, could be insufficient for normal cell growth. To increase the cellular supply of acetyl-CoA, we introduced bacterial acetylating acetaldehyde dehydrogenase (A-ALD) enzyme (EC 1.2.1.10) genes into the lactic acid-producing S. cerevisiae. Escherichia coli-derived A-ALD genes, mhpF and eutE, were expressed and effectively complemented the attenuated acetaldehyde dehydrogenase (ALD)/acetyl-CoA synthetase (ACS) pathway in the yeast. The engineered strain, possessing a heterologous acetyl-CoA synthetic pathway, showed an increased glucose consumption rate and higher productivity of lactic acid fermentation. The production of lactic acid was reached at 142g/L with production yield of 0.89g/g and productivity of 3.55gL(-1)h(-1) under fed-batch fermentation in bioreactor. This study demonstrates a novel approach that improves productivity of lactic acid by metabolic engineering of the acetyl-CoA biosynthetic pathway in yeast. PMID:26384570

  18. The role of acetyl xylan esterase in the solubilization of xylan and enzymatic hydrolysis of wheat straw and giant reed

    Zhang Junhua

    2011-12-01

    Full Text Available Abstract Background Due to the complexity of lignocellulosic materials, a complete enzymatic hydrolysis into fermentable sugars requires a variety of cellulolytic and xylanolytic enzymes. Addition of xylanases has been shown to significantly improve the performance of cellulases and to increase cellulose hydrolysis by solubilizing xylans in lignocellulosic materials. The goal of this work was to investigate the effect of acetyl xylan esterase (AXE originating from Trichoderma reesei on xylan solubilization and enzymatic hydrolysis of cellulose. Results The solubilization of xylan in pretreated wheat straw and giant reed (Arundo donax by xylanolytic enzymes and the impact of the sequential or simultaneous solubilization of xylan on the hydrolysis of cellulose by purified enzymes were investigated. The results showed that the removal of acetyl groups in xylan by AXE increased the accessibility of xylan to xylanase and improved the hydrolysis of xylan in pretreated wheat straw and giant reed. Solubilization of xylan led to an increased accessibility of cellulose to cellulases and thereby increased the hydrolysis extent of cellulose. A clear synergistic effect between cellulases and xylanolytic enzymes was observed. The highest hydrolysis yield of cellulose was obtained with a simultaneous use of cellulases, xylanase and AXE, indicating the presence of acetylated xylan within the cellulose matrix. Acetylated xylobiose and acetylated xylotriose were produced from xylan without AXE, as confirmed by atmospheric pressure matrix-assisted laser desorption/ionization ion trap mass spectrometry. Conclusions The results in this paper demonstrate that supplementation of xylanase with AXE enhances the solubilization of xylan to some extent and, consequently, increases the subsequent hydrolysis of cellulose. The highest hydrolysis yield was, however, obtained by simultaneous hydrolysis of xylan and cellulose, indicating a layered structure of cellulose and

  19. P0525 : N-Acetylated alpha smooth muscle actin levels are increased in hepatic fibrosis but decreased in hepatocellular carcinoma

    Nielsen, M.J.; Nielsen, S.H.; Hansen, N.U.B.; Kristensen, Jacob Hull; Karsdal, M.A.; Leeming, D. J.

    2015-01-01

    Alpha Smooth Muscle Actin (a-SMA) is upregulated together with extracellular matrix (ECM) during activation of Hepatic Stellate Cells (HSCs) in fibrosis. Histone deacetylase (HDAC) remove acetylations and regulate the expression of genes, which is associated with cancers. There is a close...... relationship between cirrhosis and hepatocellular carcinoma (HCC), and markers enabling identification of patients in risk of developing HCC with cirrhosis is a major unmet clinical need. We developed an ELISA for the assessment of acetylated a-SMA (Aca- SMA) in serum. The objective was to investigate the...

  20. Acetate supplementation modulates brain histone acetylation and decreases interleukin-1β expression in a rat model of neuroinflammation

    Soliman Mahmoud L

    2012-03-01

    Full Text Available Abstract Background Long-term acetate supplementation reduces neuroglial activation and cholinergic cell loss in a rat model of lipopolysaccharide-induced neuroinflammation. Additionally, a single dose of glyceryl triacetate, used to induce acetate supplementation, increases histone H3 and H4 acetylation and inhibits histone deacetylase activity and histone deacetylase-2 expression in normal rat brain. Here, we propose that the therapeutic effect of acetate in reducing neuroglial activation is due to a reversal of lipopolysaccharide-induced changes in histone acetylation and pro-inflammatory cytokine expression. Methods In this study, we examined the effect of a 28-day-dosing regimen of glyceryl triacetate, to induce acetate supplementation, on brain histone acetylation and interleukin-1β expression in a rat model of lipopolysaccharide-induced neuroinflammation. The effect was analyzed using Western blot analysis, quantitative real-time polymerase chain reaction and enzymic histone deacetylase and histone acetyltransferase assays. Statistical analysis was performed using one-way analysis of variance, parametric or nonparametric when appropriate, followed by Tukey's or Dunn's post-hoc test, respectively. Results We found that long-term acetate supplementation increased the proportion of brain histone H3 acetylated at lysine 9 (H3K9, histone H4 acetylated at lysine 8 and histone H4 acetylated at lysine 16. However, unlike a single dose of glyceryl triacetate, long-term treatment increased histone acetyltransferase activity and had no effect on histone deacetylase activity, with variable effects on brain histone deacetylase class I and II expression. In agreement with this hypothesis, neuroinflammation reduced the proportion of brain H3K9 acetylation by 50%, which was effectively reversed with acetate supplementation. Further, in rats subjected to lipopolysaccharide-induced neuroinflammation, the pro-inflammatory cytokine interleukin-1β protein

  1. Engineering cofactor and transport mechanisms in Saccharomyces cerevisiae for enhanced acetyl-CoA and polyketide biosynthesis.

    Cardenas, Javier; Da Silva, Nancy A

    2016-07-01

    Synthesis of polyketides at high titer and yield is important for producing pharmaceuticals and biorenewable chemical precursors. In this work, we engineered cofactor and transport pathways in Saccharomyces cerevisiae to increase acetyl-CoA, an important polyketide building block. The highly regulated yeast pyruvate dehydrogenase bypass pathway was supplemented by overexpressing a modified Escherichia coli pyruvate dehydrogenase complex (PDHm) that accepts NADP(+) for acetyl-CoA production. After 24h of cultivation, a 3.7-fold increase in NADPH/NADP(+) ratio was observed relative to the base strain, and a 2.2-fold increase relative to introduction of the native E. coli PDH. Both E. coli pathways increased acetyl-CoA levels approximately 2-fold relative to the yeast base strain. Combining PDHm with a ZWF1 deletion to block the major yeast NADPH biosynthesis pathway resulted in a 12-fold NADPH boost and a 2.2-fold increase in acetyl-CoA. At 48h, only this coupled approach showed increased acetyl-CoA levels, 3.0-fold higher than that of the base strain. The impact on polyketide synthesis was evaluated in a S. cerevisiae strain expressing the Gerbera hybrida 2-pyrone synthase (2-PS) for the production of the polyketide triacetic acid lactone (TAL). Titers of TAL relative to the base strain improved only 30% with the native E. coli PDH, but 3.0-fold with PDHm and 4.4-fold with PDHm in the Δzwf1 strain. Carbon was further routed toward TAL production by reducing mitochondrial transport of pyruvate and acetyl-CoA; deletions in genes POR2, MPC2, PDA1, or YAT2 each increased titer 2-3-fold over the base strain (up to 0.8g/L), and in combination to 1.4g/L. Combining the two approaches (NADPH-generating acetyl-CoA pathway plus reduced metabolite flux into the mitochondria) resulted in a final TAL titer of 1.6g/L, a 6.4-fold increase over the non-engineered yeast strain, and 35% of theoretical yield (0.16g/g glucose), the highest reported to date. These biological driving

  2. RASSF1A Suppresses Cell Migration through Inactivation of HDAC6 and Increase of Acetylated α-Tubulin

    Jung, Hae-Yun; Jung, Jun Seok; Whang, Young Mi; Kim, Yeul Hong

    2013-01-01

    Purpose The RAS association domain family protein 1 (RASSF1) has been implicated in a tumor-suppressive function through the induction of acetylated α-tubulin and modulation of cell migration. However, the mechanisms of how RASSF1A is associated with acetylation of α-tubulin for controlling cell migration have not yet been elucidated. In this study, we found that RASSF1A regulated cell migration through the regulation of histon deacetylase 6 (HDAC6), which functions as a tubulin deacetylase. ...

  3. Acetylation of RelA at discrete sites regulates distinct nuclear functions of NF-κB

    Chen, Lin-Feng; Mu, Yajun; Greene, Warner C.

    2002-01-01

    The nuclear function of the heterodimeric NF-κB transcription factor is regulated in part through reversible acetylation of its RelA subunit. We now demonstrate that the p300 and CBP acetyltransferases play a major role in the in vivo acetylation of RelA, principally targeting lysines 218, 221 and 310 for modification. Analysis of the functional properties of hypoacetylated RelA mutants containing lysine-to-arginine substitutions at these sites and of wild-type RelA co-expressed in the presen...

  4. Some properties of acetyl-CoA:arylamine N-acetyltransferase (EC 2.3.1.5) from rat pineal gland

    N-acetylation of serotonin to N-acetylserotonin in the pineal gland is catalysed by acetyl-CoA:arylamine N-acetyltransferase (SNAT). The present investigation was an attempt to design an assay technique which would permit sensitive evaluation of SNAT in order to evaluate some kinetic properties of the enzyme

  5. Engineering cytosolic acetyl-coenzyme A supply in Saccharomyces cerevisiae: Pathway stoichiometry, free-energy conservation and redox-cofactor balancing.

    van Rossum, Harmen M; Kozak, Barbara U; Pronk, Jack T; van Maris, Antonius J A

    2016-07-01

    Saccharomyces cerevisiae is an important industrial cell factory and an attractive experimental model for evaluating novel metabolic engineering strategies. Many current and potential products of this yeast require acetyl coenzyme A (acetyl-CoA) as a precursor and pathways towards these products are generally expressed in its cytosol. The native S. cerevisiae pathway for production of cytosolic acetyl-CoA consumes 2 ATP equivalents in the acetyl-CoA synthetase reaction. Catabolism of additional sugar substrate, which may be required to generate this ATP, negatively affects product yields. Here, we review alternative pathways that can be engineered into yeast to optimize supply of cytosolic acetyl-CoA as a precursor for product formation. Particular attention is paid to reaction stoichiometry, free-energy conservation and redox-cofactor balancing of alternative pathways for acetyl-CoA synthesis from glucose. A theoretical analysis of maximally attainable yields on glucose of four compounds (n-butanol, citric acid, palmitic acid and farnesene) showed a strong product dependency of the optimal pathway configuration for acetyl-CoA synthesis. Moreover, this analysis showed that combination of different acetyl-CoA production pathways may be required to achieve optimal product yields. This review underlines that an integral analysis of energy coupling and redox-cofactor balancing in precursor-supply and product-formation pathways is crucial for the design of efficient cell factories. PMID:27016336

  6. Dynamic acetylation of all lysine 4-methylated histone H3 in the mouse nucleus: analysis at c-fos and c-jun.

    Catherine A Hazzalin

    2005-12-01

    Full Text Available A major focus of current research into gene induction relates to chromatin and nucleosomal regulation, especially the significance of multiple histone modifications such as phosphorylation, acetylation, and methylation during this process. We have discovered a novel physiological characteristic of all lysine 4 (K4-methylated histone H3 in the mouse nucleus, distinguishing it from lysine 9-methylated H3. K4-methylated histone H3 is subject to continuous dynamic turnover of acetylation, whereas lysine 9-methylated H3 is not. We have previously reported dynamic histone H3 phosphorylation and acetylation as a key characteristic of the inducible proto-oncogenes c-fos and c-jun. We show here that dynamically acetylated histone H3 at these genes is also K4-methylated. Although all three modifications are proven to co-exist on the same nucleosome at these genes, phosphorylation and acetylation appear transiently during gene induction, whereas K4 methylation remains detectable throughout this process. Finally, we address the functional significance of the turnover of histone acetylation on the process of gene induction. We find that inhibition of turnover, despite causing enhanced histone acetylation at these genes, produces immediate inhibition of gene induction. These data show that all K4-methylated histone H3 is subject to the continuous action of HATs and HDACs, and indicates that at c-fos and c-jun, contrary to the predominant model, turnover and not stably enhanced acetylation is relevant for efficient gene induction.

  7. Characterisation of bacterial cellulose partly acetylated by dimethylacetamide/lithium chloride

    Cellulose is a water-insoluble polysaccharide used at an industrial scale for the manufacture of paper and films or in the dust form, natural, hydrolysed or derivatised. The cellulose produced by G. hansenii (former A. xylinum) has a structure identical to that of plants, but is free of lignin and hemicellulose, with several unique physical-chemical properties. The main barrier to the use of cellulose is its insolubility in water and most organic solvents, but soluble derivatives can be obtained with the use of ionic solvents. Bacterial cellulose, produced in a static, 4% glucose medium, was dissolved in hot DMAc/LiCl (120, 150 or 170 deg. C). The solution was analysed by 13C NMR, and the effect of the dissolution on the crystalline state was shown by X-ray crystallography. The crystalline structure was lost upon dissolution, becoming amorphous; this was also observed for Avicel plant cellulose. The soluble cellulose was partly acetylated in acetic anhydride with acetic anhydride-cellulose ratios of 1:50, 1:6 and 1:12 (w/v). The resulting cellulose acetates were examined by infrared spectroscopy, and the best result was 43% (w/v). The degree of acetylation was determined via 1H NMR spectroscopy by comparing the area of the glucose ring at 2.60-5.20 ppm and that of the methyl proton of the acetate group at 1.80-2.20 ppm. The 13C NMR spectra showed acetylation at C6 >> C2 > C3 at 60-80 ppm, with C1 signals at ∼ 100-104 ppm. The derivatisation of bacterial cellulose in DMAc/LiCl/acetic anhydride (1:4:50, v/v/v) gave rise to 87% substitution. The process of dissolution of the bacterial cellulose is essential for the analysis of the insoluble polymer in water, facilitating analysis and characterisation of these composites by 13C NMR spectroscopy, size exclusion chromatography and light scattering techniques.

  8. Characterisation of bacterial cellulose partly acetylated by dimethylacetamide/lithium chloride

    Lima, G. de Marco [PMCF-Mestrado em Ciencias Farmaceuticas, UNIVALI, ZIP 88302-202, Itajai-SC (Brazil); Sierakowski, M.-R.; Faria-Tischer, P.C.S. [BIOPOL-Biopolymers Lab. PO Box 19081, ZIP 81531-990, Curitiba-PR (Brazil); Tischer, C.A., E-mail: cesar.tischer@pq.cnpq.br [BIOPOL-Biopolymers Lab. PO Box 19081, ZIP 81531-990, Curitiba-PR (Brazil)

    2011-03-12

    Cellulose is a water-insoluble polysaccharide used at an industrial scale for the manufacture of paper and films or in the dust form, natural, hydrolysed or derivatised. The cellulose produced by G. hansenii (former A. xylinum) has a structure identical to that of plants, but is free of lignin and hemicellulose, with several unique physical-chemical properties. The main barrier to the use of cellulose is its insolubility in water and most organic solvents, but soluble derivatives can be obtained with the use of ionic solvents. Bacterial cellulose, produced in a static, 4% glucose medium, was dissolved in hot DMAc/LiCl (120, 150 or 170 deg. C). The solution was analysed by {sup 13}C NMR, and the effect of the dissolution on the crystalline state was shown by X-ray crystallography. The crystalline structure was lost upon dissolution, becoming amorphous; this was also observed for Avicel plant cellulose. The soluble cellulose was partly acetylated in acetic anhydride with acetic anhydride-cellulose ratios of 1:50, 1:6 and 1:12 (w/v). The resulting cellulose acetates were examined by infrared spectroscopy, and the best result was 43% (w/v). The degree of acetylation was determined via {sup 1}H NMR spectroscopy by comparing the area of the glucose ring at 2.60-5.20 ppm and that of the methyl proton of the acetate group at 1.80-2.20 ppm. The {sup 13}C NMR spectra showed acetylation at C6 >> C2 > C3 at 60-80 ppm, with C1 signals at {approx} 100-104 ppm. The derivatisation of bacterial cellulose in DMAc/LiCl/acetic anhydride (1:4:50, v/v/v) gave rise to 87% substitution. The process of dissolution of the bacterial cellulose is essential for the analysis of the insoluble polymer in water, facilitating analysis and characterisation of these composites by {sup 13}C NMR spectroscopy, size exclusion chromatography and light scattering techniques.

  9. Core promoter structure and genomic context reflect histone 3 lysine 9 acetylation patterns

    Arakawa Takahiro

    2010-04-01

    Full Text Available Abstract Background Histone modifications play an important role in gene regulation. Acetylation of histone 3 lysine 9 (H3K9ac is generally associated with transcription initiation and unfolded chromatin, thereby positively influencing gene expression. Deep sequencing of the 5' ends of gene transcripts using DeepCAGE delivers detailed information about the architecture and expression level of gene promoters. The combination of H3K9ac ChIP-chip and DeepCAGE in a myeloid leukemia cell line (THP-1 allowed us to study the spatial distribution of H3K9ac around promoters using a novel clustering approach. The promoter classes were analyzed for association with relevant genomic sequence features. Results We performed a clustering of 4,481 promoters according to their surrounding H3K9ac signal and analyzed the clustered promoters for association with different sequence features. The clustering revealed three groups with major H3K9ac signal upstream, centered and downstream of the promoter. Narrow single peak promoters tend to have a concentrated activity of H3K9ac in the upstream region, while broad promoters tend to have a concentrated activity of H3K9ac and RNA polymerase II binding in the centered and downstream regions. A subset of promoters with high gene expression level, compared to subsets with low and medium gene expression, shows dramatic increase in H3K9ac activity in the upstream cluster only; this may indicate that promoters in the centered and downstream clusters are predominantly regulated at post-initiation steps. Furthermore, the upstream cluster is depleted in CpG islands and more likely to regulate un-annotated genes. Conclusions Clustering core promoters according to their surrounding acetylation signal is a promising approach for the study of histone modifications. When examining promoters clustered into groups according to their surrounding H3K9 acetylation signal, we find that the relative localization and intensity of H3K9ac is

  10. Topical effects of N-acetyl-L-hydroxyproline on ceramide synthesis and alleviation of pruritus

    Hashizume E

    2013-02-01

    Full Text Available Erika Hashizume,1 Tetsuo Nakano,2 Ayako Kamimura,1 Koji Morishita31Healthcare Products Development Center, Kyowa Hakko Bio, Tsukuba, Ibaraki, 2Technical Research Laboratories, Kyowa Hakko Bio, Hofu, Yamaguchi, 3Technology Development and Research Department, Kyowa Hakko Bio, Tokyo, JapanPurpose: N-acetyl-l-hydroxyproline (AHYP is an acetylated form of l-hydroxyproline that is used to treat skin ulcers and porphyria cutanea tarda. Its other biological and physiological effects on the skin have not been elucidated. We investigated the effects of AHYP on the skin-barrier function, focusing on ceramide synthesis and the effects of topical AHYP on atopic dermatitis.Materials and methods: AHYP was applied to a three-dimensional cultured skin model. Ceramides were quantified by high-performance thin-layer chromatography. Serine palmitoyltransferase (SPT is the rate-limiting enzyme in de novo ceramide synthesis, and the mRNA of its long-chain base subunit 1 (SPTLC1 was evaluated by quantitative reverse-transcription polymerase chain reaction. A clinical trial in the form of an intraindividual, comparative, double-blind, randomized, vehicle-controlled test involving 15 female subjects suffering from slight atopic dermatitis was performed. Subjects applied 1% (w/w AHYP cream to one forearm and a control cream to the other forearm twice daily for 4 weeks. Skin condition was evaluated by measuring transepidermal water loss (TEWL. Dermatological observations were made by a dermatologist, and subjects evaluated their own pruritus intensity before beginning treatment and 4 weeks after the start of treatment.Results: SPTLC1 expression and ceramide synthesis were significantly increased in an AHYP-treated skin model (P < 0.05. In the clinical trial, no adverse effects were observed in any subjects. TEWL was increased in the control-treated region of the forearm (P < 0.05 after 4 weeks' application, whereas there was no change in the AHYP-treated region of the

  11. Characterization of the conglomerate form of acetyl-DL-leucine by thermal analysis and solubility measurements

    Estime, N.; Pena, R.; Teychené, S.; Autret, J. M.; Biscans, B.

    2012-03-01

    Starting from a mixture of enantiomers in solution, crystallization can generate different types of crystals. In order to determine which type of crystal is obtained in the case of acetyl leucine, an active pharmaceutical ingredient (API), analytical methods have been used to partially elucidate the binary and ternary phase diagrams of the system composed of the two enantiomers and water. The melting temperature phase diagram of this compound has been obtained by using differential scanning calorimetry (DSC) analyzes. The results show that it is characteristic of a conglomerate. This mode of crystallization has also been confirmed by X-ray powder diffraction analysis. Solubility measurements of enantiomerical mixtures in water enabled the determination of the ternary diagram of solubility. The empiric Meyerhoffer double solubility rule has been modified, due to the characterization of interactions between enantiomers.

  12. Periodic Mesoporous Organosilica Functionalized with Sulfonic Acid Groups as Acid Catalyst for Glycerol Acetylation

    Pascal Van Der Voort

    2013-08-01

    Full Text Available A Periodic Mesoporous Organosilica (PMO functionalized with sulfonic acid groups has been successfully synthesized via a sequence of post-synthetic modification steps of a trans-ethenylene bridged PMO material. The double bond is functionalized via a bromination and subsequent substitution obtaining a thiol functionality. This is followed by an oxidation towards a sulfonic acid group. After full characterization, the solid acid catalyst is used in the acetylation of glycerol. The catalytic reactivity and reusability of the sulfonic acid modified PMO material is investigated. The catalyst showed a catalytic activity and kinetics that are comparable with the commercially available resin, Amberlyst-15, and furthermore our catalyst can be recycled for several subsequent catalytic runs and retains its catalytic activity.

  13. Chemicals loading in acetylated bamboo assisted by supercritical CO2 based on phase equilibrium data

    Silviana, Petermann, M.

    2015-12-01

    Indonesia has a large tropical forest. However, the deforestation still appears annually and vastly. This reason drives a use of bamboo as wood alternative. Recently, there are many modifications of bamboo in order to prolong the shelf life. Unfortunately, the processes need more chemicals and time. Based on wood modification, esterifying of bamboo was undertaken in present of a dense gas, i.e. supercritical CO2. Calculation of chemicals loading referred to ASTM D1413-99 by using the phase equilibrium data at optimum condition by a statistical design. The results showed that the acetylation of bamboo assisted by supercritical CO2 required 14.73 kg acetic anhydride/m3 of bamboo for a treatment of one hour.

  14. Acetylated cashew gum-based nanoparticles for transdermal delivery of diclofenac diethyl amine.

    Dias, Sávia Francisca Lopes; Nogueira, Silvania Siqueira; de França Dourado, Flaviane; Guimarães, Maria Adelaide; de Oliveira Pitombeira, Nádia Aline; Gobbo, Graciely Gomides; Primo, Fernando Lucas; de Paula, Regina Célia Monteiro; Feitosa, Judith Pessoa Andrade; Tedesco, Antonio Claudio; Nunes, Lívio Cesar Cunha; Leite, José Roberto Souza Almeida; da Silva, Durcilene Alves

    2016-06-01

    Nanoprecipitation and dialysis methods were employed to obtain nanoparticles (NPs) of acetylated cashew gum (ACG). NPs synthesized by dialysis showed greater average size compared to those synthesized by nanoprecipitation, but they presented improved stability and yield. NPs were loaded with diclofenac diethylamine and the efficiency of the drug incorporation was over 60% for both methods, for an ACG:NP a weight ratio of 10:1. The cytotoxicity assay demonstrated that the NPs had no significant effect on the cell viability, verifying their biocompatibility. The release profile for the diclofenac diethylamine associated with the ACG-NPs showed a more controlled release compared to the free drug and a Fickian diffusion mechanism was observed. Transdermal permeation reached 90% penetration of the drug. PMID:27083367

  15. Metabolomic Analysis of Blood Plasma after Oral Administration of N-acetyl-d-Glucosamine in Dogs

    Tomohiro Osaki

    2015-08-01

    Full Text Available N-acetyl-d-glucosamine (GlcNAc is a monosaccharide that polymerizes linearly through (1,4-β-linkages. GlcNAc is the monomeric unit of the polymer chitin. GlcNAc is a basic component of hyaluronic acid and keratin sulfate found on the cell surface. The aim of this study was to examine amino acid metabolism after oral GlcNAc administration in dogs. Results showed that plasma levels of ectoine were significantly higher after oral administration of GlcNAc than prior to administration (p < 0.001. To our knowledge, there have been no reports of increased ectoine concentrations in the plasma. The mechanism by which GlcNAc administration leads to increased ectoine plasma concentration remains unclear; future studies are required to clarify this mechanism.

  16. Metabolite regulation of the interaction between Arabidopsis thaliana PII and N-acetyl-l-glutamate kinase.

    Feria Bourrellier, Ana Belén; Ferrario-Méry, Sylvie; Vidal, Jean; Hodges, Michael

    2009-10-01

    The metabolic control of the interaction between ArabidopsisN-acetyl-l-glutamate kinase (NAGK) and the PII protein has been studied. Both gel exclusion and affinity chromatography analyses of recombinant, affinity-purified PII (trimeric complex) and NAGK (hexameric complex) showed that NAGK strongly interacted with PII only in the presence of Mg-ATP, and that this process was reversed by 2-oxoglutarate (2-OG). Furthermore, metabolites such as arginine, glutamate, citrate, and oxalacetate also exerted a negative effect on the PII-NAGK complex formation in the presence of Mg-ATP. Using chloroplast protein extracts and PII affinity chromatography, NAGK interacted with PII only in the presence of ATP-Mg(2+), and this process was antagonized by 2-OG. These results reveal a complex metabolic control of the PII interaction with NAGK in the chloroplast stroma of higher plants. PMID:19631611

  17. Versatile colorant syntheses by multiple condensations of acetyl anilines with perylene anhydrides.

    Jänsch, Daniel; Li, Chen; Chen, Long; Wagner, Manfred; Müllen, Klaus

    2015-02-01

    We report a key step forward in rylene chemistry: the transformation of rylenes into novel chromophore families. The imidization of rylene anhydrides with 2-acetyl anilines could be controlled by the choice of the solvent, thus causing a transformation into either a 4-hydroxyquinoline (4-HQ) or a 4-oxoquinoline (4-OQ) unit. The 4-OQ motif contains an aminoenone group formed by intramolecular aldol condensation and is the first vinylogous rylene imide. The concept of vinylogy was further developed by utilizing 2,6-diacetyl aniline leading to an 3a-aza-1,6-phenalenedione-extended rylene skeleton fully embracing the nitrogen atom. By functionalization of the aminoenone motifs, for example, malononitrile addition at the carbonyl groups, the optical and electronic properties could be further tuned. PMID:25586519

  18. FT-Raman and FTIR-ATR spectroscopies and DFT calculations of triterpene acetyl aleuritolic acid

    Melo, I. R. S.; Teixeira, A. M. R.; Sena Junior, D. M.; Santos, H. S.; Albuquerque, M. R. J. R.; Bandeira, P. N.; Rodrigues, A. S.; Braz-Filho, R.; Gusmão, G. O. M.; Silva, J. H.; Faria, J. L. B.; Bento, R. R. F.

    2014-01-01

    Triterpenoids comprise an important class of compounds presenting a wide range of biologically important properties. Acetyl aleutitolic acid (AAA) is a triterpenoid isolated from Croton zehntneri, with molecular formula C32H50O4. Its structure has been characterized by NMR spectroscopy, however, there are no papers available regarding its vibrational properties. The Fourier-Transform Infrared with Attenuated Total Reflectance and Fourier-Transform Raman spectra, together with Density Functional Theory calculations of AAA are reported. Vibrational spectra were recorded at 300 K in the regions 600 cm-1 to 4000 cm-1 and 40 cm-1 to 4000 cm-1, for IR and Raman, respectively. Vibrational wavenumbers were predicted using Density Functional Theory calculations with the hybrid functional B3LYP and the basis set 6-31 G(d,p). A complete assignment of vibrational modes is given.

  19. Hydrophobication and characterisation of O-acetyl-galactoglucomannan for papermaking and barrier applications.

    Kisonen, Victor; Eklund, Patrik; Auer, Markku; Sjöholm, Rainer; Pranovich, Andrey; Hemming, Jarl; Sundberg, Anna; Aseyev, Vladimir; Willför, Stefan

    2012-05-01

    Norway spruce O-acetyl-galactoglucomannans (GGM) are water-soluble hemicelluloses that have potential to be produced in large scale as a side product of the mechanical pulping industry or by hot-water extraction of wood. Chemical modification is often needed to tailor such water-soluble polysaccharides into industrially valuable compounds. In this work, treatment of GGM with butyric and benzoic anhydride in pyridine/dimethylformamide rendered GGM derivatives, which were hydrophobic and partially soluble in organic solvents. The degree of substitution can be adjusted by varying the quantity of the reagent and reaction temperature. The dn/dc value for the benzoyl ester of GGM was determined in 0.05 M LiBr DMSO in order to obtain accurate molar mass analysis with SEC-MALLS-RI. Novel substances with adjusted hydrophobicity can thus be prepared on one step synthesis from natural hemicelluloses, which then showed a slight increase in the molar mass upon esterification. PMID:22370176

  20. Acetyl CoA Carboxylase 2 Is Dispensable for CD8+ T Cell Responses.

    Jang Eun Lee

    Full Text Available Differentiation of T cells is closely associated with dynamic changes in nutrient and energy metabolism. However, the extent to which specific metabolic pathways and molecular components are determinative of CD8+ T cell fate remains unclear. It has been previously established in various tissues that acetyl CoA carboxylase 2 (ACC2 regulates fatty acid oxidation (FAO by inhibiting carnitine palmitoyltransferase 1 (CPT1, a rate-limiting enzyme of FAO in mitochondria. Here, we explore the cell-intrinsic role of ACC2 in T cell immunity in response to infections. We report here that ACC2 deficiency results in a marginal increase of cellular FAO in CD8+ T cells, but does not appear to influence antigen-specific effector and memory CD8+ T cell responses during infection with listeria or lymphocytic choriomeningitis virus. These results suggest that ACC2 is dispensable for CD8+ T cell responses.

  1. Synthesis of (2-pyridyl)-Acetyl Chitosan and Its Antioxidant Activity

    Li, Rongchun [Dezhou Univ., Dezhou (China)

    2011-10-15

    In this paper, chloracetyl chitosan (CACTS) was prepared at first. In the molecules of CACTS, there are active chlorine groups, which can take part in other reactions. Thus, number of chitosan derivatives will be obtained after chlorine is substituted. Choosing pyridine as the active group, a novel water-soluble chitosan derivative, (2-pyridyl)-acetyl chitosan (PACTS) was obtained and its antioxidant activity against hydroxyl radicals and superoxide radicals was assessed. The results indicated that PACTS had better antioxidant activity than that of chitosan, carboxymethyl chitosan (CMCTS), hydroxypropyl chitosan (HPCTS), and Vitamin C. And the IC{sub 50} values against hydroxyl radicals and superoxide radicals were 0.31 mg/mL and 0.21 mg/mL, respectively.

  2. A chromodomain switch mediated by histone H3 Lys 4 acetylation regulates heterochromatin assembly

    Xhemalce, Blerta; Kouzarides, Tony

    2010-01-01

    Chromodomain proteins (Chp1/Chp2/Swi6/Clr4) bind to methylated H3K9 (H3K9me) and regulate pericentric heterochromatin in fission yeast. Chp1 and Clr4 (H3K9-HMT), bind transcriptionally active heterochromatin, whereas Chp2/Swi6 (HP1 homologs) are recruited during the inactive state. We show that H3K4 acetylation (H3K4ac) plays a role in the transition of dimethylated H3K9 (H3K9me2) occupancy from Chp1/Clr4 to Chp2/Swi6. H3K4ac, mediated by Mst1, is enriched at pericentromeres concomitantly wit...

  3. Immunological Features of Severe Bronchial Asthma in Children with Different Acetylation Types

    Svetlana Tarnavska

    2015-03-01

    Full Text Available Conducting a comprehensive clinical and paraclinical examinations of 53 children with severe asthma made it possible to establish the relative increase in the content of CD 22-lymphocytes (relative risk – 2.1 odds ratio - 3.8 and interleukin-5 (relative risk – 1.8 odds ratio - 3.4 in the serum of the patients with fast acetylatic status that reflected the implementation of the respiratory tract eosinophilic inflammation. In children with a slow acetylation phenotype severe asthma probably has been formed with the participation of other mechanisms that reflected the correlation of IL-8 with increased functional activity of blood neutrophils according to NBT-test (r = 0,5; p <0, 05 and bronchial hyperresponsiveness (r = 0,9; p <0,05.

  4. Effects of aeration on formation and localization of the acetyl coenzyme A synthetases of Saccharomyces cerevisiae

    Klein, H. P.; Jahnke, L.

    1979-01-01

    Previous studies on the yeast Saccharomyces cerevisiae have shown that two different forms of the enzyme acetyl coenzyme A synthetase (ACS) are present, depending on the conditions under which the cells are grown. The paper evaluates the usefulness of a method designed to assay both synthetases simultaneously in yeast homogenates. The data presented confirm the possibility of simultaneous detection and estimation of the amount of both ACSs of S. cerevisiae in crude homogenates of this strain, making possible the study of physiological factors involved in the formation of these isoenzymes. One important factor for specifying which of the two enzymes is found in these yeast cells is the presence or absence of oxygen in their environment. Aeration not only affects the ratio of the two ACSs but also appears to affect the cellular distribution of these enzymes. Most of the data presented suggest the possibility that the nonaerobic ACS may serve as a precursor to the aerobic form.

  5. Synthesis of (2-pyridyl)-Acetyl Chitosan and Its Antioxidant Activity

    In this paper, chloracetyl chitosan (CACTS) was prepared at first. In the molecules of CACTS, there are active chlorine groups, which can take part in other reactions. Thus, number of chitosan derivatives will be obtained after chlorine is substituted. Choosing pyridine as the active group, a novel water-soluble chitosan derivative, (2-pyridyl)-acetyl chitosan (PACTS) was obtained and its antioxidant activity against hydroxyl radicals and superoxide radicals was assessed. The results indicated that PACTS had better antioxidant activity than that of chitosan, carboxymethyl chitosan (CMCTS), hydroxypropyl chitosan (HPCTS), and Vitamin C. And the IC50 values against hydroxyl radicals and superoxide radicals were 0.31 mg/mL and 0.21 mg/mL, respectively

  6. Identification of a bacterial pectin acetyl esterase in Erwinia chrysanthemi 3937.

    Shevchik, V E; Hugouvieux-Cotte-Pattat, N

    1997-06-01

    Erwinia chrysanthemi causes soft-rot diseases of various plants by enzymatic degradation of the pectin in plant cell walls. The structural complexity of pectin requires the combined action of several pectinases for its efficient breakdown. Three types of pectinases have so far been identified in E. chrysanthemi: two pectin methyl esterases (PemA, PemB), a polygalacturonase (PehX), and eight pectate lyases (PelA, PelB, PelC, PelD, PelE, PelL, PelZ, PelX). We report in this paper the analysis of a novel enzyme, the pectin acetyl esterase encoded by the paeY gene. No bacterial form of pectin acetyl esterases has been described previously, while plant tissues and some pectinolytic fungi were found to produce similar enzymes. The paeY gene is present in a cluster of five pectinase-encoding genes, pelA-pelE-pelD-paeY-pemA. The paeY open reading frame is 1650 bases long and encodes a 551-residue precursor protein of 60704Da, including a 25-amino-acid signal peptide. PaeY shares one region of homology with a rhamnogalacturonan acetyl esterase of Aspergillus aculeatus. To characterize the enzyme, the paeY gene was overexpressed and its protein product was purified. PaeY releases acetate from sugar-beet pectin and from various synthetic substrates. Moreover, the enzyme was shown to act in synergy with other pectinases. The de-esterification rate by PaeY increased after previous demethylation of the pectins by PemA and after depolymerization of the pectin by pectate lyases. In addition, the degradation of sugar-beet pectin by pectate lyases is favoured after the removal of methyl and acetyl groups by PemA and PaeY, respectively. The paeY gene was first identified on the basis of its regulation, which shares several characteristics with that of other pectinases. Analysis of the paeY transcription, using gene fusions, revealed that it is induced by pectic catabolic products and is affected by growth phase, oxygen limitation and catabolite repression. Regulation of pae

  7. [Epigenetics and drug addiction: a focus on MeCP2 and on histone acetylation].

    Zwiller, Jean

    2015-04-01

    Chronic drug exposure alters gene expression in the brain, which is believed to underlie compulsive drug seeking and drug taking behavior. Recent evidence shows that drug-induced long-term neuroadaptations in the brain are mediated in part by epigenetic mechanisms. By remodeling chromatin, this type of regulation contributes to drug-induced synaptic plasticity that translates into behavioral modifications. How drug-induced alterations in DNA methylation regulate gene expression is reviewed here, with a focus on MeCP2, a protein binding methylated DNA. The importance of histone modifications, especially acetylation is also discussed, with an emphasis on the effects of inhibitors of histone deacetylases on drug-induced behavioral changes. The precise identification of the epigenetic mechanisms that are under the control of drugs of abuse may help to uncover novel targets for the treatment of drug seeking and relapse. PMID:25958763

  8. Effect of shock wave reapplication on urinary n-acetyl-beta-glucosaminidase in canine kidney

    Marco A.Q.R. Fortes

    2004-04-01

    Full Text Available OBJECTIVE: Renal tubular damage can be assessed with the aid of urinary dosing of N-acetyl-beta-glucosaminidase (NAG and it is possible to demonstrate a significant correlation between shock wave and damage to renal parenchyma. The objective of this study was to assess the effect of shock wave reapplication over urinary NAG in canine kidney. MATERIALS AND METHODS: The authors submitted 10 crossbred dogs to 2 applications of 2000 shock waves in a 24-hour interval in order to assess urinary NAG values after 12, 24, 36 and 48 hours. RESULTS: Twelve hours following the first shockwave application there was an increase in NAG of 6.47 ± 5.44 u/g creatinine (p 0.05. CONCLUSION: Shock wave reapplication with a 24-hour interval did not cause any increase in urinary NAG.

  9. A STUDY OF THE EFFECT OF ACETYLATION ON HEMP FIBRES WITH VINYL ACETATE

    Nilgül Özmen

    2012-07-01

    Full Text Available Chemical modifications of hemp fibers were performed with acetic anhydride (AA and vinyl acetate (VA in the presence of pyridine or potassium carbonate as catalysts. Hemp fibers (Cannabis sativa were successfully acetylated by VA in the presence of potassium carbonate (15% WPG, but no weight gain was obtained when pyridine was used as catalyst. Hemp fibers were also modified with acetic anhydride (AA in the presence of potassium carbonate and pyridine as catalyst (14% and 16% WPG, respectively under identical conditions, and the results were compared with those obtained using the VA technique. AA-modified, VA-modified, and control hemp fibers were characterized by Infrared (FTIR, 13C CP MAS NMR and thermo gravimetric analysis (TGA.

  10. [Acetyl-CoA cleavage and synthesis in methanogens]. Progress report, September 1994--August 1997

    NONE

    1998-11-01

    The acetyl-CoA decarbonylase synthase (ACDS) complex has been detected in a variety of methanogens including species of Methanosarcina, Methanothrix (i.e., Methanosaeta), and Methanococcus. The multienzyme complex from Methanosarcina barkeri is composed of five different subunits, possibly arranged in an {alpha}{sub 6}{beta}{sub 6}{gamma}{sub 6}{delta}{sub 6}{var_epsilon}{sub 6} structure with the individual subunits of molecular masses (kDa) of 89, 60, 50, 48, and 20, respectively. This progress report summarizes the work from the past 21 months on studies directed toward understanding how the ACDS complex functions in the physiology of acetate-cleaving, and acetate-synthesizing methanogens.

  11. Crystal structure of 3-acetyl-4H-chromen-4-one

    Yoshinobu Ishikawa

    2015-07-01

    Full Text Available In the title compound, C11H8O3, the fused-ring system is almost planar (r.m.s. deviation = 0.020 Å, with the largest deviation from the least-squares plane [0.0462 (17 Å] being for a pyran C atom. The dihedral angle between the plane of the fused-ring system and acetyl plane is 5.149 (16°. In the crystal, the fused rings are linked by aromatic π–π stacking interactions [centroid–centroid distance between the benzene and pyran rings = 3.643 (6 Å] and C—H...O hydrogen bonds, generating a three-dimensional network.

  12. ATRA transcriptionally induces nSMase2 through CBP/p300-mediated histone acetylation.

    Clarke, Christopher J; Shamseddine, Achraf A; Jacob, Joseph J; Khalife, Gabrielle; Burns, Tara A; Hannun, Yusuf A

    2016-05-01

    Neutral sphingomyelinase-2 (nSMase2) is a key ceramide-producing enzyme in cellular stress responses. While many posttranslational regulators of nSMase2 are known, emerging evidence suggests a more protracted regulation of nSMase2 at the transcriptional level. Previously, we reported that nSMase2 is induced by all-trans retinoic acid (ATRA) in MCF7 cells and implicated nSMase2 in ATRA-induced growth arrest. Here, we further investigated how ATRA regulates nSMase2. We find that ATRA regulates nSMase2 transcriptionally through the retinoic acid receptor-α, but this is independent of previously identified transcriptional regulators of nSMase2 (Sp1, Sp3, Runx2) and is not through increased promoter activity. Epigenetically, the nSMase2 gene is not repressively methylated in MCF7 cells. However, inhibition of histone deacetylases (HDACs) with trichostatin A (TSA) induced nSMase2 comparably to ATRA; furthermore, combined ATRA and TSA treatment was not additive, suggesting ATRA regulates nSMase2 through direct modulation of histone acetylation. Confirming this, the histone acetyltransferases CREB-binding protein and p300 were required for ATRA induction of nSMase2. Finally, use of class-specific HDAC inhibitors suggested that HDAC4 and/or HDAC5 are negative regulators of nSMase2 expression. Collectively, these results identify a novel pathway of nSMase2 regulation and suggest that physiological or pharmacological modulation of histone acetylation can directly affect nSMase2 levels. PMID:27013100

  13. N-[3H]acetyl-labeling, a convenient method for radiolabeling of glycosaminoglycans

    A method for the introduction of N-[3H]acetyl groups into glycosaminoglycans is described. The procedure is based on [3H]acetylation of N-unsubstituted hexosamine residues by treating the polysaccharides with [3H]acetic anhydride. Preparations of heparin and heparin sulfate were found to contain significant numbers of N-unsubstituted hexosamine residues, as isolates. In contrast, such units could not be detected in chondroitin sulfate, dermatan sulfate, or hyaluronic acid. These polysaccharides were therefore subjected to partial N-deacetylation by reaction with hydrazine in the presence of hydrazine sulfate. After treatment with [3H]acetic anhydride, the specific activities of the resulting labeled polysaccharide preparations ranged between 0.1 X 106 and 0.6 X 106 cpm 3H/μg of uronic acid. The 3H-labeled polysaccharide preparations did not differ significantly from the corresponding unlabeled starting materials with regard to polyanion properties (chromatography on DEAE-cellulose) or polymer chain size (gel chromatography). Further, the radiolabeled polysaccharide derivatives were susceptible to specific enzymatic degradation (chondroitinase ABC and mammalian heparitinase) and retained their ability to interact specifically with certain proteins - for example, [3H]heparin with antithrombin [3H]hyaluronic acid oligosaccharides with chondroitin sulfate proteoglycan. These findings indicate that the labeling procedures did not induce any major structural derangement of the polysaccharide molecules. The method developed should be useful in providing labeled glycosaminoglycans for metabolic and enzymatic experiments as well as for studies on the interacion between glycosaminoglycans and other bilogical macromolecules

  14. N-(/sup 3/H)acetyl-labeling, a convenient method for radiolabeling of glycosaminoglycans

    Hook, M.; Riesenfeld, J.; Lindahl, U.

    1982-01-15

    A method for the introduction of N-(/sup 3/H)acetyl groups into glycosaminoglycans is described. The procedure is based on (/sup 3/H)acetylation of N-unsubstituted hexosamine residues by treating the polysaccharides with (/sup 3/H)acetic anhydride. Preparations of heparin and heparin sulfate were found to contain significant numbers of N-unsubstituted hexosamine residues, as isolates. In contrast, such units could not be detected in chondroitin sulfate, dermatan sulfate, or hyaluronic acid. These polysaccharides were therefore subjected to partial N-deacetylation by reaction with hydrazine in the presence of hydrazine sulfate. After treatment with (/sup 3/H)acetic anhydride, the specific activities of the resulting labeled polysaccharide preparations ranged between 0.1 X 10/sup 6/ and 0.6 X 10/sup 6/ cpm /sup 3/H/..mu..g of uronic acid. The /sup 3/H-labeled polysaccharide preparations did not differ significantly from the corresponding unlabeled starting materials with regard to polyanion properties (chromatography on DEAE-cellulose) or polymer chain size (gel chromatography). Further, the radiolabeled polysaccharide derivatives were susceptible to specific enzymatic degradation (chondroitinase ABC and mammalian heparitinase) and retained their ability to interact specifically with certain proteins - for example, (/sup 3/H)heparin with antithrombin (/sup 3/H)hyaluronic acid oligosaccharides with chondroitin sulfate proteoglycan. These findings indicate that the labeling procedures did not induce any major structural derangement of the polysaccharide molecules. The method developed should be useful in providing labeled glycosaminoglycans for metabolic and enzymatic experiments as well as for studies on the interacion between glycosaminoglycans and other bilogical macromolecules.

  15. What Are the Potential Sites of Protein Arylation by N-Acetyl-p-benzoquinone Imine (NAPQI)?

    Leeming, Michael G; Gamon, Luke F; Wille, Uta; Donald, William A; O'Hair, Richard A J

    2015-11-16

    Acetaminophen (paracetamol, APAP) is a safe and widely used analgesic medication when taken at therapeutic doses. However, APAP can cause potentially fatal hepatotoxicity when taken in overdose or in patients with metabolic irregularities. The production of the electrophilic and putatively toxic compound N-acetyl-p-benzoquinone imine (NAPQI), which cannot be efficiently detoxicated at high doses, is implicated in APAP toxicity. Numerous studies have identified that excess NAPQI can form covalent linkages to the thiol side chains of cysteine residues in proteins; however, the reactivity of NAPQI toward other amino acid side chains is largely unexplored. Here, we report a survey of the reactivity of NAPQI toward 11 N-acetyl amino acid methyl esters and four peptides. (1)H NMR analysis reveals that NAPQI forms covalent bonds to the side-chain functional groups of cysteine, methionine, tyrosine, and tryptophan residues. Analogous reaction products were observed when NAPQI was reacted with synthetic model peptides GAIL-X-GAILR for X = Cys, Met, Tyr, and Trp. Tandem mass spectrometry peptide sequencing showed that the NAPQI modification sites are located on the "X" residue in each case. However, when APAP and the GAIL-X-GAILR peptide were incubated with rat liver microsomes that contain many metabolic enzymes, NAPQI formed by oxidative metabolism reacted with GAIL-C-GAILR exclusively. For the peptides where X = Met, Tyr, and Trp, competing reactions between NAPQI and alternative nucleophiles precluded arylation of the target peptide by NAPQI. Although Cys residues are favorably targeted under these conditions, these data suggest that NAPQI can, in principle, also damage proteins at Met, Tyr, and Trp residues. PMID:26523953

  16. Formation of [b(n) + 17 + Ag]+ product ions from Ag+ cationized native and acetylated peptides.

    Anbalagan, V; Perera, B A; Silva, A T M; Gallardo, A L; Barber, M; Barr, J M; Terkarli, S M; Talaty, E R; Van Stipdonk, M J

    2002-09-01

    We compared the tandem mass spectra of a range of native and acetylated Ag(+) cationized peptides to determine the influence of the derivatization step on the abundance of the [b(n) + 17 + Ag](+) product ions. Using tripeptides, the smallest for which the mechanisms to generate [b(2) - 1 + Ag](+) and [b(2) + 17 + Ag](+) products are both operative, we found that in most cases acetylation causes an increase in the abundance of the C-terminal rearrangement ion, [b(2) + 17 + Ag](+), relative to the rival N-terminal rearrangement ion, [b(2) - 1 + Ag](+). The presence of a free amino group to bind to the metal ion significantly influences the relative abundances of the product ions. We propose a mechanism for the formation of the [b(n) + 17 + Ag](+) that is based on the formation of a five-membered oxazolidin-5-one and tetrahedral carbon intermediate that may collapse to a peptide upon release of CO and an imine, aided by the fact that the ring formed during C-terminal rearrangement is both a hemiacylal and hemiaminal. We also identified an influence of amino acid sequence on the relative abundances of the [b(n) + 17 + Ag](+) and [b(n) - 1 + Ag](+) product ions, whereby bulky substituents located on the alpha-carbon of the amino acid to the C-terminal side of the cleavage site apparently promote the formation of the [b(n) + 17 + Ag](+) product over [b(n) - 1 + Ag](+) when the amino acid to the N-terminal side of the cleavage site is glycine. The latter ion is the favored product, however, when the bulky group is positioned on the alpha-carbon of the amino acid to the N-terminal side of the cleavage site. PMID:12271434

  17. N Acetyl Cysteine, A novel Remedy for Poly Cystic Ovarian Syndrome

    Nasibeh Amirzargar

    2009-01-01

    Full Text Available Background: Poly cystic ovarian syndrome (PCOS is the most prevalent endocrinopathy among womenand the most common underlying diagnosis for anovulatory infertility. The role of insulin-resistance(IR and hyperinsulinemia in pathophysiology and clinical manifestations of the syndrome depicts theimportance of evaluation of the efficacy of insulin reducing medications. N acetyl cysteine (NAC inhibitsoxidative stress and prevents hyperglycemia induced insulin resistance. This study aims at evaluating theeffects of NAC on manifestations of the disease as well as improvement of fertility status.Materials and Methods: Through a prospective double-blind clinical trial, 46 patients were randomlydivided into one intervention and one control group. The two groups were treated for six weeks aftersimilarity was allocated. All clinical and biochemical indicators were recorded in the early follicularphase both before and after treatment.Results: From each group, 18 patients were ultimately evaluated. In the first group, ovulation rateincreased as compared to the control group. A significant decrease in weight, body mass index (BMI,and waist/hip ratio was also observed. Fast blood sugar (FBS, serum insulin, total cholesterol, lowdensity lipoprotein (LDL levels, and HOMA-IR index also dropped while high density lipoproteinHDL levels elevated significantly. No significant change was reported in luteinizing hormone (LH,FSH, PRL, LH/FSH levels and glucose/insulin ratio. The control group remained unchanged.Conclusion: N- Acetyl Cysteine improves lipid profile, hormonal levels, ovulation status, and longtermhealth of women with PCOS. Considering its limited adverse effects, it can be regarded as asubstitute for insulin reducing medications in treatment of these patients.

  18. Neuroprotection in rabbit retina with N-acetyl-aspartylglutamate and 2-phosphonyl-methyl pentanedioic acid

    Hacker, Henry D.; Yourick, Debra L.; Koenig, Michael K.; Slusher, Barbara S.; Meyerhoff, James L.

    1999-06-01

    Retinal tissue is subject to ischemia from diabetic retinopathy and other conditions that affect the retinal vasculature such as lupus erythematosus and temporal arteritis. There is evidence in animal models of reversible ischemia that a therapeutic window exists during early recovery when agents that reduce glutamate activity at its receptor sites can rescue neurons from injury. To model ischemia, we used sodium cyanide (NaCN), to inhibit oxidative metabolism, and 2-deoxyglucose (2-DG) to inhibit glycolysis. Dissociated rabbit retina cells were studied to evaluate the potential neuroprotective effects of N-acetyl-aspartyl-glutamate (MAAG), which competes with glutamate as a low-potency agonist at the NMDA receptor complex. N-acetylated α-linked acidic dipeptidase (NAALADase; the NAAG-hydrolyzing enzyme) is responsible for the hydrolysis of NAAG into glutamate, a neurotransmitter and potent excitotoxin, and N-acetylaspartate. 2-Phosphonyl-methyl pentanedioic acid (PMPA) and β-linked NAAG (β-NAAG), inhibitors of NAALADase, were also tested, since inhibition of NAALADase could reduce synaptic glutamate and increase the concentration of NAAG. We found that metabolic inhibition with NaCN/2-DG for 1 hour caused 50% toxicity as assessed with the MTT assay. Co-treatment with NAAG resulted in dose-dependent protection of up to 55% (p<0.005). When the non-hydrolyzable, NAALADase inhibitor β-NAAG was employed dose-dependent protection of up to 37% was observed (p<0.001). PMPA also showed 48% protection (p<.05-.001) against these insults. These data suggest that NAAG may antagonize the effect of glutamate at the NMDA receptor complex in retina. Inhibition of NAALADase by PMPA and β-NAAG may increase the activity of endogenous NAAG.

  19. Stability of carboplatin, paclitaxel, and docetaxel with acetyl-l-carnitine during simulated Y-site administration.

    Zhang, Yang; Scarlett, Cameron; Hutson, Paul

    2012-01-01

    The compatibility of acetyl-l-carnitine with three chemotherapy agents was studied during simulated Y-site administration. Acetyl-l-carnitine 30 mg/mL in 5% dextrose for injection (D5W) was combined with carboplatin 4 mg/mL, paclitaxel 2 mg/mL, and docetaxel 0.74 mg/mL in glass vials. Physical compatibility over the 4-hour storage at room temperature was assessed by visual examinations with unaided eye under fluorescent light and by measuring the percent transmittance at 600 nm. Chemical compatibility was measured by the percent of initial concentration remaining using stability-indicating high-performance liquid chromatographic-ultraviolet and high-performance liquid chromatographic-mass spectrometry methods. No visible particulate matter, haze, or color change was observed, and the percent transmittance was >95% for all admixtures. After a 4-hour incubation, 93.2% of the paclitaxel and 96.5% of docetaxel remained in separate mixtures with acetyl-l-carnitine. Carboplatin 4 mg/mL, paclitaxel 1.2 mg/mL, and docetaxel 0.74 mg/mL are physically and chemically compatible with acetyl-l-carnitine 30 mg/mLin D5W during a simulated 4-hour Y-site administration. PMID:23050317

  20. Impaired Coenzyme A metabolism affects histone and tubulin acetylation in Drosophila and human cell models of pantothenate kinase associated neurodegeneration

    Siudeja, Katarzyna; Srinivasan, Balaji; Xu, Lanjun; Rana, Anil; de Jong, Jannie; Nollen, Ellen A. A.; Jackowski, Suzanne; Sanford, Lynn; Hayflick, Susan; Sibon, Ody C. M.

    2011-01-01

    Pantothenate kinase-associated neurodegeneration (PKAN is a neurodegenerative disease with unresolved pathophysiology. Previously, we observed reduced Coenzyme A levels in a Drosophila model for PKAN. Coenzyme A is required for acetyl-Coenzyme A synthesis and acyl groups from the latter are transfer

  1. Iodine Supported on 3-Aminopropyl Silica Gel as Efficient Catalyst for Acetylation of Alcohols under Solvent-free Conditions

    MAHDAVI Hossein; GHAEMY Mosa; ZERAATPISHEH Fatemeh

    2009-01-01

    3-Aminopropyl silica gel (I2/APSG) was found to catalyze the acetylation of alcohols and phenols efficiently with acetic anhydride. The reaction is mild and selective with high yields. A wide variety of alcohols and phenols are selectively converted into the corresponding acetates using I2/APSG under solvent-free conditions at room tem-perature.

  2. Biosynthesis of 2-acetyl-1-pyrroline in rice calli cultures: Demonstration of 1-pyrroline as a limiting substrate.

    Poonlaphdecha, Janchai; Gantet, Pascal; Maraval, Isabelle; Sauvage, François-Xavier; Menut, Chantal; Morère, Alain; Boulanger, Renaud; Wüst, Matthias; Gunata, Ziya

    2016-04-15

    The role of 1-pyrroline was studied via feeding experiments using rice calli cultures to gain further insight into the key steps of 2-acetyl-1-pyrroline (2AP) biosynthesis in rice. The origin of the acetyl donor was also studied through stable isotope labelled substrates. Incubation of fresh calli from a fragrant rice variety (Aychade) and a non-fragrant variety (Gladio×Fidji K2) with 1-pyrroline led to a significant increase in 2AP in both varieties. Importantly, the amount of 2AP in the non-fragrant variety could be greatly enhanced by this supplementation. When rice calli were fed with increasing levels of 1-pyrroline, 2AP levels increased accordingly. Our data show that 1-pyrroline is a limiting factor for 2AP synthesis in rice. Heat treatment of calli suggested that 1-pyrroline might be enzymatically acetylated. The presence of labelled 2AP in calli supplemented with [U-(13)C]glucose, sodium acetate (1,2-(13)C2) and sodium octanoate (1,2,3,4-(13)C4) suggested that these compounds are possible candidates for acetyl group-donors of 2AP, predominately in the form of intact labelled (13)C2-units. PMID:26617041

  3. Wnt Protein Signaling Reduces Nuclear Acetyl-CoA Levels to Suppress Gene Expression during Osteoblast Differentiation.

    Karner, Courtney M; Esen, Emel; Chen, Jiakun; Hsu, Fong-Fu; Turk, John; Long, Fanxin

    2016-06-17

    Developmental signals in metazoans play critical roles in inducing cell differentiation from multipotent progenitors. The existing paradigm posits that the signals operate directly through their downstream transcription factors to activate expression of cell type-specific genes, which are the hallmark of cell identity. We have investigated the mechanism through which Wnt signaling induces osteoblast differentiation in an osteoblast-adipocyte bipotent progenitor cell line. Unexpectedly, Wnt3a acutely suppresses the expression of a large number of genes while inducing osteoblast differentiation. The suppressed genes include Pparg and Cebpa, which encode adipocyte-specifying transcription factors and suppression of which is sufficient to induce osteoblast differentiation. The large scale gene suppression induced by Wnt3a corresponds to a global decrease in histone acetylation, an epigenetic modification that is associated with gene activation. Mechanistically, Wnt3a does not alter histone acetyltransferase or deacetylase activities but, rather, decreases the level of acetyl-CoA in the nucleus. The Wnt-induced decrease in histone acetylation is independent of β-catenin signaling but, rather, correlates with suppression of glucose metabolism in the tricarboxylic acid cycle. Functionally, preventing histone deacetylation by increasing nucleocytoplasmic acetyl-CoA levels impairs Wnt3a-induced osteoblast differentiation. Thus, Wnt signaling induces osteoblast differentiation in part through histone deacetylation and epigenetic suppression of an alternative cell fate. PMID:27129247

  4. p300-mediated acetylation of the Rothmund-Thomson-syndrome gene product RECQL4 regulates its subcellular localization

    Dietschy, T.; Shevelev, Igor; Pena-Diaz, J.; Hühn, D.; Kuenzle, S.; Mak, R.; Miah, M.F.; Hess, D.; Fey, M.; Hottiger, M.O.; Janščák, Pavel; Stagljar, I.

    2009-01-01

    Roč. 122, Pt 8 (2009), s. 1258-1267. ISSN 0021-9533 Institutional research plan: CEZ:AV0Z50520514 Keywords : RECQL4 * RecQ helicases * Genome stability * p300 * Protein acetylation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.144, year: 2009

  5. Generation of acetyl free radicals by radiolysis: comparison of free radicals generated from acetaldehyde and ethylene-glycol

    The optical absorption spectra of the intermediates obtained by pulse radiolysis of N2O-saturated solutions of acetaldehyde or ethylene-glycol and the kinetics of their decays have been investigated. Results suggest that the OH· radical reactions with acetaldehyde or ethylene-glycol produce acetyl and formylmethyl radicals. Besides, these radicals are shown to reduce ferricytochrome c

  6. Structure and Reactivity of the N-Acetyl-Cysteine Radical Cation and Anion: Does Radical Migration Occur?

    Osburn, S.; G. Berden,; Oomens, J.; O' Hair, R. A. J.; Ryzhov, V.

    2011-01-01

    The structure and reactivity of the N-acetyl-cysteine radical cation and anion were studied using ion-molecule reactions, infrared multi-photon dissociation (IRMPD) spectroscopy, and density functional theory (DFT) calculations. The radical cation was generated by first nitrosylating the thiol of N-

  7. Computational Study of Environmental Effects on Torsional Free Energy Surface of N-Acetyl-N'-methyl-L-alanylamide Dipeptide

    Carlotto, Silvia; Zerbetto, Mirco

    2014-01-01

    We propose an articulated computational experiment in which both quantum mechanics (QM) and molecular mechanics (MM) methods are employed to investigate environment effects on the free energy surface for the backbone dihedral angles rotation of the small dipeptide N-Acetyl-N'-methyl-L-alanylamide. This computation exercise is appropriate for an…

  8. Acetylation of p65 at lysine 314 is important for late NF-κB-dependent gene expression

    Hottiger Michael O

    2010-01-01

    Full Text Available Abstract Background NF-κB regulates the expression of a large number of target genes involved in the immune and inflammatory response, apoptosis, cell proliferation, differentiation and survival. We have earlier reported that p65, a subunit of NF-κB, is acetylated in vitro and in vivo at three different lysines (K310, K314 and K315 by the histone acetyltransferase p300. Results In this study, we describe that site-specific mutation of p65 at lysines 314 and 315 enhances gene expression of a subset of NF-κB target genes including Mmp10 and Mmp13. Increased gene expression was mainly observed three hours after TNFα stimulation. Chromatin immunoprecipitation (ChIP experiments with an antibody raised against acetylated lysine 314 revealed that chromatin-bound p65 is indeed acetylated at lysine 314. Conclusions Together, our results establish acetylation of K314 as an important regulatory modification of p65 and subsequently of NF-κB-dependent gene expression.

  9. Heterologous Expression and Characterization of an N-Acetyl-beta-D-hexosaminidase from Lactococcus lactis ssp. lactis IL1403

    Nguyen, A. H.; Nguyen, T.-H.; Křen, Vladimír; Eijsink, V. G. H.; Haltrich, D.; Peterbauer, C.

    2012-01-01

    Roč. 60, č. 12 (2012), s. 3275-3281. ISSN 0021-8561 R&D Projects: GA ČR(CZ) GAP207/11/0629 Keywords : N-acetyl-beta-D-hexosaminidase * Lactococcus lactis ssp lactis IL1403 * pNP-GlcNAc Subject RIV: CE - Biochemistry Impact factor: 2.906, year: 2012

  10. N,O6-partially acetylated chitosan nanoparticles hydrophobically-modified for controlled release of steroids and vitamin E

    Quinones, Javier Perez; Gothelf, Kurt Vesterager; Kjems, Jørgen;

    2013-01-01

    Diosgenin, two synthetic analogs of brassinosteroids, testosterone and dl-α-tocopherol were covalently linked to synthetic water-soluble N,O6-partially acetylated chitosan, for their controlled release. Drug linking was confirmed by FTIR spectroscopy and proton NMR. Conjugates were also character...

  11. Enzymatically hydrolysed, acetylated and dually modified corn starch: physico-chemical, rheological and nutritional properties and effects on cake quality.

    Sahnoun, Mouna; Ismail, Nouha; Kammoun, Radhouane

    2016-01-01

    Corn starch was treated by enzymatic hydrolysis with Aspergillus oryzae S2 α-amylase, acetylation with vinyl acetate, and dual modification. The dual modified starch displayed a higher substitution degree than the acetylated starch and lower reducing sugar content than the hydrolysed starch. The results revealed that the cooling viscosity and amylose content of those products decrease (P oil absorption capacity was observed for the acetylated starch and, which was less pronounced for the enzymatically hydrolysed starch but more pronounced for the enzymatically hydrolysed acetylated product. The latter product underwent an increase in resistant starch content, which is induced by a rise in hydrolysis time to attain about 67 % after 1 h of reaction. The modified starch samples were added to cake formulations at 5 and 10 % concentrations on a wheat flour basis and compared to native starch. The results revealed that when applied at 5 % concentrations, the modified starches reduced the hardness, cohesion, adhesion and chewiness of baked cakes and enhanced their elasticity, volume, height, crust color, and appearance as compared to native starch. These effects were more pronounced for the cake incorporating the dually modified starch. PMID:26787967

  12. INTERFERENCE OF CARBAMYLATED AND ACETYLATED HEMOGLOBINS IN ASSAYS OF GLYCOHEMOGLOBIN BY HPLC, ELECTROPHORESIS, AFFINITY-CHROMATOGRAPHY, AND ENZYME-IMMUNOASSAY

    WEYKAMP, CW; PENDERS, TJ; SIEBELDER, CWM; MUSKIET, FAJ; VANDERSLIK, W

    1993-01-01

    In vitro-synthesized carbamylated and acetylated hemoglobins interfered in assays of glycohemoglobin by HPLC and electrophoresis but had no effects on results obtained by affinity chromatography and enzyme immunoassay. Correlations between long-term serum urea concentrations and glycohemoglobin perc

  13. A multienzyme complex channels substrates and electrons through acetyl-CoA and methane biosynthesis pathways in Methanosarcina.

    Dillon J Lieber

    Full Text Available Multienzyme complexes catalyze important metabolic reactions in many organisms, but little is known about the complexes involved in biological methane production (methanogenesis. A crosslinking-mass spectrometry (XL-MS strategy was employed to identify proteins associated with coenzyme M-coenzyme B heterodisulfide reductase (Hdr, an essential enzyme in all methane-producing archaea (methanogens. In Methanosarcina acetivorans, Hdr forms a multienzyme complex with acetyl-CoA decarbonylase synthase (ACDS, and F420-dependent methylene-H4MPT reductase (Mer. ACDS is essential for production of acetyl-CoA during growth on methanol, or for methanogenesis from acetate, whereas Mer is essential for methanogenesis from all substrates. Existence of a Hdr:ACDS:Mer complex is consistent with growth phenotypes of ACDS and Mer mutant strains in which the complex samples the redox status of electron carriers and directs carbon flux to acetyl-CoA or methanogenesis. We propose the Hdr:ACDS:Mer complex comprises a special class of multienzyme redox complex which functions as a "biological router" that physically links methanogenesis and acetyl-CoA biosynthesis pathways.

  14. Cortical N-acetyl aspartate is a predictor of long-term clinical disability in multiple sclerosis

    Wu, Xingchen; Hanson, Lars G.; Skimminge, Arnold Jesper Møller;

    2014-01-01

    Objective: To evaluate the prognostic value of the cortical N-acetyl aspartate to creatine ratio (NAA/Cr) in early relapsing-remitting multiple sclerosis (RRMS). Methods: Sixteen patients with newly diagnosed RRMS were studied by serial MRI and MR spectroscopic imaging (MRSI) once every 6 months ...

  15. Neural-network analysis of the vibrational spectra of N-acetyl L-alanyl N '-methyl amide conformational states

    Bohr, Henrik; Frimand, Kenneth; Jalkanen, Karl J.;

    2001-01-01

    Density-functional theory (DFT) calculations utilizing the Becke 3LYP hybrid functional have been carried out for N-acetyl L-alanine N'-methylamide and examined with respect to the effect of water on the structure, the vibrational frequencies, vibrational absorption (VA), vibrational circular dic...

  16. Global Histone H4 Acetylation in the Olfactory Bulb of Lactating Rats with Different Patterns of Maternal Behavior.

    de Moura, Ana Carolina; da Silva, Ivy Reichert Vital; Reinaldo, Gustavo; Dani, Caroline; Elsner, Viviane Rostirola; Giovenardi, Márcia

    2016-10-01

    In rats, variations in the levels of neuromodulatory molecules and in the expression of their receptors are observed during pregnancy and postpartum. These changes may contribute to the development and management of maternal behavior. The frequency of licking the pups is used to evaluate maternal care, having mothers with low licking (LL) and high licking (HL) frequencies. Previously, we found that HL had increased levels of transcriptional expression of the receptors for serotonin (HTR1a, HTR1b), estrogen (Erα), dopamine (D1a), and prolactin (Prlr) than LL in the olfactory bulb (OB); however, the molecular mechanisms behind this phenomenon are unknown. Since evidences pointed out that epigenetic marks, which may alter gene expression, are modulated by environmental factors such as exercise, diet, maternal care, and xenobiotic exposure, our objective was to verify the acetylation levels of histone-H4 in the OB of LL and HL rats. Maternal behavior was studied for the first 7 postpartum days. LL (n = 4) and HL (n = 5) mothers were selected according to the behavior of licking their pups. Acetylation levels of histone-H4 were determined using the Global Histone-H4 Acetylation Assay Kit and expressed as ng/mg protein (mean ± SD). Analysis revealed that HL (278.36 ± 68.95) had increased H4 acetylation levels than LL (183.24 ± 73.05; p = 0.045). The enhanced expression of the previously studied receptors in the OB could be related, at least in part, to the hyperacetylation status of histone-H4 here observed. Afterward, the modulation of histone acetylation levels could exert a pivotal role through molecular mechanisms involved in the different patterns of maternal behavior. PMID:26620050

  17. `Up-regulation of histone acetylation induced by social defeat mediates the conditioned rewarding effects of cocaine.

    Montagud-Romero, S; Montesinos, J; Pascual, M; Aguilar, M A; Roger-Sanchez, C; Guerri, C; Miñarro, J; Rodríguez-Arias, M

    2016-10-01

    Social defeat (SD) induces a long-lasting increase in the rewarding effects of psychostimulants measured using the self-administration and conditioned place procedures (CPP). However, little is known about the epigenetic changes induced by social stress and about their role in the increased response to the rewarding effects of psychostimulants. Considering that histone acetylation regulates transcriptional activity and contributes to drug-induced behavioral changes, we addressed the hypothesis that SD induces transcriptional changes by histone modifications associated with the acquisition of place conditioning. After a fourth defeat, H3(K9) acetylation was decreased in the hippocampus, while there was an increase of HAT and a decrease of HDAC levels in the cortex. Three weeks after the last defeat, mice displayed an increase in histone H4(K12) acetylation and an upregulation of histone acetyl transferase (HAT) activity in the hippocampus. In addition, H3(K4)me3, which is closely associated with transcriptional initiation, was also augmented in the hippocampus three weeks after the last defeat. Inhibition of HAT by curcumin (100mg/kg) before each SD blocked the increase in the conditioned reinforcing effects of 1mg/kg of cocaine, while inhibition of HDAC by valproic acid (500mg/kg) before social stress potentiated cocaine-induced CPP. Preference was reinstated when animals received a priming dose of 0.5mg/kg of cocaine, an effect that was absent in untreated defeated mice. These results suggest that the experience of SD induces chromatin remodeling, alters histone acetylation and methylation, and modifies the effects of cocaine on place conditioning. They also point to epigenetic mechanisms as potential avenues leading to new treatments for the long-term effects of social stress on drug addiction. PMID:27180319

  18. Deep, Quantitative Coverage of the Lysine Acetylome Using Novel Anti-acetyl-lysine Antibodies and an Optimized Proteomic Workflow.

    Svinkina, Tanya; Gu, Hongbo; Silva, Jeffrey C; Mertins, Philipp; Qiao, Jana; Fereshetian, Shaunt; Jaffe, Jacob D; Kuhn, Eric; Udeshi, Namrata D; Carr, Steven A

    2015-09-01

    Introduction of antibodies specific for acetylated lysine has significantly improved the detection of endogenous acetylation sites by mass spectrometry. Here, we describe a new, commercially available mixture of anti-lysine acetylation (Kac) antibodies and show its utility for in-depth profiling of the acetylome. Specifically, seven complementary monoclones with high specificity for Kac were combined into a final anti-Kac reagent which results in at least a twofold increase in identification of Kac peptides over a commonly used Kac antibody. We outline optimal antibody usage conditions, effective offline basic reversed phase separation, and use of state-of-the-art LC-MS technology for achieving unprecedented coverage of the acetylome. The methods were applied to quantify acetylation sites in suberoylanilide hydroxamic acid-treated Jurkat cells. Over 10,000 Kac peptides from over 3000 Kac proteins were quantified from a single stable isotope labeling by amino acids in cell culture labeled sample using 7.5 mg of peptide input per state. This constitutes the deepest coverage of acetylation sites in quantitative experiments obtained to-date. The approach was also applied to breast tumor xenograft samples using isobaric mass tag labeling of peptides (iTRAQ4, TMT6 and TMT10-plex reagents) for quantification. Greater than 6700 Kac peptides from over 2300 Kac proteins were quantified using 1 mg of tumor protein per iTRAQ 4-plex channel. The novel reagents and methods we describe here enable quantitative, global acetylome analyses with depth and sensitivity approaching that obtained for other well-studied post-translational modifications such as phosphorylation and ubiquitylation, and should have widespread application in biological and clinical studies employing mass spectrometry-based proteomics. PMID:25953088

  19. Myofibril growth during cardiac hypertrophy is regulated through dual phosphorylation and acetylation of the actin capping protein CapZ.

    Lin, Ying-Hsi; Warren, Chad M; Li, Jieli; McKinsey, Timothy A; Russell, Brenda

    2016-08-01

    The mechanotransduction signaling pathways initiated in heart muscle by increased mechanical loading are known to lead to long-term transcriptional changes and hypertrophy, but the rapid events for adaptation at the sarcomeric level are not fully understood. The goal of this study was to test the hypothesis that actin filament assembly during cardiomyocyte growth is regulated by post-translational modifications (PTMs) of CapZβ1. In rapidly hypertrophying neonatal rat ventricular myocytes (NRVMs) stimulated by phenylephrine (PE), two-dimensional gel electrophoresis (2DGE) of CapZβ1 revealed a shift toward more negative charge. Consistent with this, mass spectrometry identified CapZβ1 phosphorylation on serine-204 and acetylation on lysine-199, two residues which are near the actin binding surface of CapZβ1. Ectopic expression of dominant negative PKCɛ (dnPKCɛ) in NRVMs blunted the PE-induced increase in CapZ dynamics, as evidenced by the kinetic constant (Kfrap) of fluorescence recovery after photobleaching (FRAP), and concomitantly reduced phosphorylation and acetylation of CapZβ1. Furthermore, inhibition of class I histone deacetylases (HDACs) increased lysine-199 acetylation on CapZβ1, which increased Kfrap of CapZ and stimulated actin dynamics. Finally, we show that PE treatment of NRVMs results in decreased binding of HDAC3 to myofibrils, suggesting a signal-dependent mechanism for the regulation of sarcomere-associated CapZβ1 acetylation. Taken together, this dual regulation through phosphorylation and acetylation of CapZβ1 provides a novel model for the regulation of myofibril growth during cardiac hypertrophy. PMID:27185186

  20. Metabolic engineering of oilseed crops to produce high levels of novel acetyl glyceride oils with reduced viscosity, freezing point and calorific value.

    Liu, Jinjie; Rice, Adam; McGlew, Kathleen; Shaw, Vincent; Park, Hyunwoo; Clemente, Tom; Pollard, Mike; Ohlrogge, John; Durrett, Timothy P

    2015-08-01

    Seed oils have proved recalcitrant to modification for the production of industrially useful lipids. Here, we demonstrate the successful metabolic engineering and subsequent field production of an oilseed crop with the highest accumulation of unusual oil achieved so far in transgenic plants. Previously, expression of the Euonymus alatus diacylglycerol acetyltransferase (EaDAcT) gene in wild-type Arabidopsis seeds resulted in the accumulation of 45 mol% of unusual 3-acetyl-1,2-diacyl-sn-glycerols (acetyl-TAGs) in the seed oil (Durrett et al., 2010 PNAS 107:9464). Expression of EaDAcT in dgat1 mutants compromised in their ability to synthesize regular triacylglycerols increased acetyl-TAGs to 65 mol%. Camelina and soybean transformed with the EaDAcT gene accumulate acetyl-triacylglycerols (acetyl-TAGs) at up to 70 mol% of seed oil. A similar strategy of coexpression of EaDAcT together with RNAi suppression of DGAT1 increased acetyl-TAG levels to up to 85 mol% in field-grown transgenic Camelina. Additionally, total moles of triacylglycerol (TAG) per seed increased 20%. Analysis of the acetyl-TAG fraction revealed a twofold reduction in very long chain fatty acids (VLCFA), consistent with their displacement from the sn-3 position by acetate. Seed germination remained high, and seedlings were able to metabolize the stored acetyl-TAGs as rapidly as regular triacylglycerols. Viscosity, freezing point and caloric content of the Camelina acetyl-TAG oils were reduced, enabling use of this oil in several nonfood and food applications. PMID:25756355

  1. Lactose-egg yolk diluent supplemented with N-acetyl-D-glucosamine affect acrosome morphology and motility of frozen-thawed boar sperm.

    Yi, Y J; Im, G S; Park, C S

    2002-12-16

    These experiments were carried out to investigate the effect of N-acetyl-D-glucosamine, and to obtain additional information about the effect of orvus es paste (OEP) and egg yolk concentration in the freezing of boar sperm in the maxi-straw. The highest post-thaw acrosomes of normal apical ridge (NAR) and motility were obtained with 0.025 or 0.05% N-acetyl-D-glucosamine concentration in the first diluent. However, there were no effects of N-acetyl-D-glucosamine among the diluents with or without N-acetyl-D-glucosamine at the second dilution. The N-acetyl-D-glucosamine in the first and second diluents was added at room temperatures (20-23 degrees C) and 5 degrees C, respectively. It is suggested that the temperature of N-acetyl-D-glucosamine addition is important for the effect of boar sperm protection during freezing and thawing. When the 0.05% N-acetyl-D-glucosamine was supplemented in the first diluent, the optimum final OEP content was 0.5%. The optimum content of egg yolk in the diluent with 0.05% N-acetyl-D-glucosamine concentration was 20% and egg yolk was one of the main cryoprotective agents. In conclusion, we found out that the diluent with 0.025 or 0.05% soluble N-acetyl-D-glucosamine in the first diluent, 0.5% final orvus es paste concentration and 20% egg yolk concentration significantly enhanced NAR acrosomes and motility of boar sperm after freezing and thawing. PMID:12417120

  2. A New Approach to Prepare 2-Acetyl-Mono (5,6,7,8)-Nitro-1,2,3,4-Tetrahydroisoquinolines

    2000-01-01

    N-Acetyl-p, m or o-nitro-phenylethylamines and (HCHO)n were treated in 60% H2SO4/HOAc, via α-amidoalkylation to give 2-acetyl-mono(5, 6, 7 or 8)-nitro-1,2,3,4-tetrahydro-isoquinolines.Additionally, some interesting phenomena were observed when the comparison between 2-acetyl-5, 6, 7 or 8-nitro-1,2,3,4-tetrahydroisoquinolines and 2-alkylsulfonyl-5 , 6 or 7- nitro-1,2,3,4-tetrahydroisoquinolines was made.

  3. MeIQx-induced DNA adduct formation and mutagenesis in DNA repair deficient CHO cells expressing human CYP1A1 and rapid or slow acetylator NAT2

    Bendaly, Jean; Zhao, Shuang; Neale, Jason R.; Metry, Kristin J.; Doll, Mark A; States, J. Christopher; Pierce, William M.; Hein, David W.

    2007-01-01

    2-Amino-3,8-dimethylimidazo-[4,5-f]quinoxaline (MeIQx) is one of the most potent and abundant mutagens in the western diet. Bioactivation includes N-hydroxylation catalyzed by cytochrome P450s followed by O-acetylation catalyzed by N-acetyltransferase 2 (NAT2). Nucleotide excision repair-deficient chinese hamster ovary (CHO) cells were constructed by stable transfection of human cytochrome P4501A1 (CYP1A1) and a single copy of either NAT2*4 (rapid acetylator) or NAT2*5B (slow acetylator) alle...

  4. Structure Elucidation of New Acetylated Saponins, Lessoniosides A, B, C, D, and E, and Non-Acetylated Saponins, Lessoniosides F and G, from the Viscera of the Sea Cucumber Holothuria lessoni

    Yadollah Bahrami; Franco, Christopher M. M.

    2015-01-01

    Sea cucumbers produce numerous compounds with a wide range of chemical structural diversity. Among these, saponins are the most diverse and include sulfated, non-sulfated, acetylated and methylated congeners with different aglycone and sugar moieties. In this study, MALDI and ESI tandem mass spectrometry, in the positive ion mode, were used to elucidate the structure of new saponins extracted from the viscera of H. lessoni. Fragmentation of the aglycone provided structural information on th...

  5. Structural aspects of the solvation shell of lysine and acetylated lysine: A Car-Parrinello and classical molecular dynamics investigation

    Carnevale, V.; Raugei, S.

    2009-12-01

    Lysine acetylation is a post-translational modification, which modulates the affinity of protein-protein and/or protein-DNA complexes. Its crucial role as a switch in signaling pathways highlights the relevance of charged chemical groups in determining the interactions between water and biomolecules. A great effort has been recently devoted to assess the reliability of classical molecular dynamics simulations in describing the solvation properties of charged moieties. In the spirit of these investigations, we performed classical and Car-Parrinello molecular dynamics simulations on lysine and acetylated-lysine in aqueous solution. A comparative analysis between the two computational schemes is presented with a focus on the first solvation shell of the charged groups. An accurate structural analysis unveils subtle, yet statistically significant, differences which are discussed in connection to the significant electronic density charge transfer occurring between the solute and the surrounding water molecules.

  6. Structural aspects of the solvation shell of lysine and acetylated lysine: A Car-Parrinello and classical molecular dynamics investigation

    Lysine acetylation is a post-translational modification, which modulates the affinity of protein-protein and/or protein-DNA complexes. Its crucial role as a switch in signaling pathways highlights the relevance of charged chemical groups in determining the interactions between water and biomolecules. A great effort has been recently devoted to assess the reliability of classical molecular dynamics simulations in describing the solvation properties of charged moieties. In the spirit of these investigations, we performed classical and Car-Parrinello molecular dynamics simulations on lysine and acetylated-lysine in aqueous solution. A comparative analysis between the two computational schemes is presented with a focus on the first solvation shell of the charged groups. An accurate structural analysis unveils subtle, yet statistically significant, differences which are discussed in connection to the significant electronic density charge transfer occurring between the solute and the surrounding water molecules.

  7. Relationships between choline acetyl-transferase and muscarinic binding in aging rodent brain and in Alzheimers disease

    This paper examines how the relation between ChAT and muscarinic binding might be affected by aging in mouse and rat brains. Preliminary data are presented regarding this relation in postmortem cerebral cortex samples from human subjects who died with Alzheimer's disease (AD) and from age-matched controls. The effect of acetyl coenzme A (1- C 14-acetyl coenzyme A concentration on enzyme activity was determined by varying the concentration of the coenzyme in the assay medium. Assays of muscarinic binding were performed on tissue sonicates diluted with Tris-HC1 buffer using tritium-quinuclidinyl benzilate tritium-QNB as the ligand. For brain regions obtained from rats, significance of age differences were assessed by one-way analysis of variance and Bonferroni t statistics. Differences in ChAT activity and binding site density from human postmortem samples between diagnostic groups were assessed separately by region using an analysis of covariance

  8. Polylactide/acetylated nanocrystalline cellulose composites prepared by a continuous route: A phase interface-property relation study.

    Xu, Chunjiang; Chen, Jianxiang; Wu, Defeng; Chen, Yang; Lv, Qiaolian; Wang, Mengqi

    2016-08-01

    A 'continuous route' was developed in this work for the preparation of nanocrystalline cellulose (NCC) filled polylactide (PLA) composites. It combines several separated steps, including extraction of NCC, surface acetylation of NCC, and final composite preparation, into a continuous process, without traditional freeze drying. The obtained PLA composites were then studied in terms of phase interface structure, rheological and mechanical properties. The results reveal that surface acetylation of NCC can improve its affinity to PLA evidently. The thickened interfacial layer makes the system filled with modified NCC show lower percolation threshold than the one filled with pristine NCC; and the former presents a typical strain-scaling stress overshoot behavior in the start-up shear flow because the network structure of modified NCC presents stronger characteristics of self-similarity. The phase interface adhesion also plays an important role in the mechanical behavior of PLA/NCC composites, which is further revealed by the nanomechanical analysis using atom force microscopy. PMID:27112851

  9. Inhibitory Activity of Synthesized Acetylated Procyanidin B1 Analogs against HeLa S3 Cells Proliferation

    Syuhei Okamoto

    2014-02-01

    Full Text Available Proanthocyanidins, also known as condensed tannins and/or oligomeric flavonoids, occur in many edible plants and have various interesting biological activities. Previously, we reported a synthetic method for the preparation of various procyanidins in pure form and described their biological activities. Here, we describe the synthesis of procyanidin B1 acetylated analogs and discuss their inhibition activities against HeLa S3 cell proliferation. Surprisingly, the lower-unit acetylated procyanidin B1 strongly inhibited the proliferation of HeLa S3 cells. This molecule showed much stronger inhibitory activity than did epigallocatechin-3-O-gallate (EGCG, green tea polyphenol, and dimeric compounds that included EGCG as a unit. This result suggests that the phenolic hydroxyl groups of the upper-units in flavan-3-ols are important for their inhibitory activity against cancer cell proliferation and that a hydrophobic lower unit dimer enhances this activity.

  10. Studies on Ion-molecule Reaction of Disubstituted Benzene with IonSystem of Acetyl Chloride in Gas Phase

    2000-01-01

    The ion-molecule reactions of disubstituted benzenes with the ion system of acetyl chloride under the chemical ionization condition were examined and the fragmentation reactions of the adduct ions formed by the ion-molecule reactions were studied by using collision-induced dissocia tion technique. It was found that the electron-releasing groups favored the adduct reactions and the electron-withdrawing groups did not. The position and properties of substituting groups had an effect on the relative abundance of the adduct ions. The fragmentation reaction of the adduct ions formed by ortho-benzene diamine with the acetyl ion was similar to the reductive alkylation reaction of amine in condensed phase.

  11. EFFECTS OF ORGANOPHOSPHATES ON ACUTE POISONING AND ACETYL CHOLINESTERASE INHIBITION IN ZEBRA FISH

    TH Sukirtha* MV Usharani

    2013-03-01

    Full Text Available Organophosphates (Ops. are the most widely used insecticides available today. These are a group of insecticides used in chemical sprays to kill bugs, and insects in orchards, vineyards, vegetables and cereal crops. The present study examined effects of the pesticide Methyl parathion, Dichlorvos and Chlorpyrifos on adult zebra fish were exposed to various concentrations (5, 10 & 25mg/L for 24 and 48hrs acute toxic study. Chlorpyrifos showed mortality in all concentrations and Methyl parathion and Dichlorvos showed the same in 25 mg/L. LC 50 value for Methyl parathion and Dichlorvos was 5 & 10 mg/L respectively. The total protein, LPO content was increased except SOD, Catalase in the brain tissue of the treated fishes.  There was no significant decrease in the GPX activity at 5ppm test groups. The GPX activity decreased significantly in test group treated with 10ppm and a significant difference was found between 5ppm and 10ppm test groups. The histopathological studies of brain tissue showed that neuronal degeneration and tissue damages in the brain of treated fishes when compared with the control. Ops. produce toxicity by inhibiting the cholinesterase enzymes in the nervous system. Monitoring of acetyl cholinesterase (AChE inhibition has been widely used in terrestrial and freshwater aquatic systems as an indicator of OP exposure and effects.

  12. The effect of N-acetyl-L-cysteine on the viscosity of ileal neobladder mucus.

    Schrier, B P; Lichtendonk, W J; Witjes, J A

    2002-05-01

    N-acetyl-L-cysteine (NAC) proved to be an effective mucolytic in pulmonary secretions. Our goal was to investigate the in vitro effect of NAC on viscosity of ileal neobladder mucus. The urine of a patient with an ileal neobladder was collected during the first 7 days postoperatively and stored in a refrigerator. After precipitation, the urine was decanted. The residue was stirred to a homogeneous suspension. To samples of 4.5 ml mucus, 0.5 ml NAC 10% was added. To the control sample, 0.5 ml water was added. The samples were incubated in a water bath at 37 degrees C for 5, 30 and 60 min. Viscosity was measured in the Bohlin VOR Rheometer. The viscosity of the ileal neobladder mucus decreased quickly after incubating with NAC 10%. Viscosity increased slightly after I h of incubation. The viscosity in the control sample was higher than in the other incubated samples. NAC was found to decrease the viscosity of ileal neobladder mucus, supporting the in vivo experience that NAC can be useful in patients with an ileal neobladder to facilitate the evacuation of mucus by decreasing viscosity. PMID:12088194

  13. N-Acetyl Cysteine in the Treatment of Obsessive Compulsive and Related Disorders: A Systematic Review

    Oliver, Georgina; Dean, Olivia; Camfield, David; Blair-West, Scott; Ng, Chee; Berk, Michael; Sarris, Jerome

    2015-01-01

    Objective Obsessive compulsive and related disorders are a collection of debilitating psychiatric disorders in which the role of glutamate dysfunction in the underpinning neurobiology is becoming well established. N-acetyl cysteine (NAC) is a glutamate modulator with promising therapeutic effect. This paper presents a systematic review of clinical trials and case reports exploring the use of NAC for these disorders. A further objective was to detail the methodology of current clinical trials being conducted in the area. Methods PubMed, Web of Science and Cochrane Library Database were searched for human clinical trials or case reports investigating NAC in the treatment of obsessive compulsive disorder (OCD) or obsessive compulsive related disorders. Researchers with known involvement in NAC studies were contacted for any unpublished data. Results Four clinical trials and five case reports/series were identified. Study durations were commonly 12-weeks, using 2,400–3,000 mg/day of NAC. Overall, NAC demonstrates activity in reducing the severity of symptoms, with a good tolerability profile and minimal adverse effects. Currently there are three ongoing randomized controlled trials using NAC for OCD (two adults and one pediatric), and one for excoriation. Conclusion Encouraging results have been demonstrated from the few pilot studies that have been conducted. These results are detailed, in addition to a discussion of future potential research. PMID:25912534

  14. Lipozyme TL IM as Catalyst for the Synthesis of Eugenyl Acetate in Solvent-Free Acetylation.

    Silva, María José A; Loss, Raquel A; Laroque, Denise A; Lerin, Lindomar A; Pereira, Gabriela N; Thon, Élise; Oliveira, J Vladimir; Ninow, Jorge L; Hense, Haiko; Oliveira, Débora

    2015-06-01

    The ability of commercial immobilized lipase from Thermomyces lanuginosus (Lipozyme TL IM) to catalyze the acetylation of essential clove oil with acetic anhydride in a solvent-free system was studied, and the antimicrobial activity of the ester formed was evaluated as well. Experimental design based on two variables (eugenol to acetic anhydride molar ratio and temperature) was employed to evaluate the experimental conditions of eugenyl acetate ester production. The maximum conversion yield (92.86 %) was obtained using Lipozyme TL IM (5 wt%, based on the total amount of substrates), with eugenol to acetic anhydride molar ratio of 1:5 at 70 °C. The chemical structure of the eugenyl acetate ester obtained at the optimized condition, and purified, was confirmed by the proton nuclear magnetic resonance ((1)H-NMR) analysis. The antimicrobial activity of eugenyl acetate ester was proven effective on Gram-positive and Gram-negative bacteria, with means of 16.62 and 17.55 mm of inhibition halo. PMID:25875787

  15. N-Acetyl Cysteine Inhibits Endothelin-1-Induced ROS Dependent Cardiac Hypertrophy through Superoxide Dismutase Regulation

    Sobia Mushtaq

    2015-07-01

    Full Text Available Objective: Oxidative stress down regulates antioxidant enzymes including superoxide dismutase (SOD and contributes to the development of cardiac hypertrophy. N-Acetyl cysteine (NAC can enhance the SOD activity, so the aim of this study is to highlight the inhibitory role of NAC against endothelin-1 (ET-1-induced cardiac hypertrophy. Materials and Methods: In this experimental study at QAU from January, 2013 to March, 2013. ET-1 (50 μg/kg and NAC (50 mg/kg were given intraperitoneally to 6-day old neonatal rats in combination or alone. All rats were sacrificed 15 days after the final injection. Histological analysis was carried out to observe the effects caused by both drugs. Reactive oxygen species (ROS analysis and SOD assay were also carried out. Expression level of hypertrophic marker, brain natriuretic peptide (BNP, was detected by western blotting. Results: Our findings showed that ET-1-induced cardiac hypertrophy leading towards heart failure was due to the imbalance of different parameters including free radical-induced oxidative stress and antioxidative enzymes such as SOD. Furthermore NAC acted as an antioxidant and played inhibitory role against ROS-dependent hypertrophy via regulatory role of SOD as a result of oxidative response associated with hypertrophy. Conclusion: ET-1-induced hypertrophic response is associated with increased ROS production and decreased SOD level, while NAC plays a role against free radicals-induced oxidative stress via SOD regulation.

  16. 2-acetyl-4-tetrahydroxybutylimidazole and 4-methylimidazole in caramel colours, vinegar and beverages in China.

    Wang, Liying; Ren, Beibei; Liu, Yinping; Lu, Yang; Chang, Fengqi; Yang, Lixin

    2015-01-01

    A survey of 2-acetyl-4-tetrahydroxybutylimidazole (THI) and 4-methylimidazole (4-MeI) concentrations in caramel colours, vinegar and beverages from the Chinese market were performed by ultrahigh-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). In total, 117 samples, 78 caramel colour samples, 23 vinegar samples and 16 beverage samples, were investigated. The results indicated that 4-MeI was found in all samples. THI was found in a part of the samples and also the level range was lower compared to 4-MeI. In caramel colour samples, the concentration level range of THI was 1.0-74.3 mg/kg and of 4-MeI was 1.5-1291.8 mg/kg. In vinegar samples, the concentration level range of THI was 13.3-119.2 µg/L and for 4-MeI 111.2-2077.8 µg/L. In beverage samples, THI was only found in two samples and the concentration level range of 4-MeI was 10.8-307.1 µg/L. THI and 4-MeI levels in vinegar and beverages were rather low compared with those in caramel colour samples. These observations can be helpful for evaluating individual exposure to THI and 4-MeI from caramel colours, vinegar and beverages in China. PMID:25832559

  17. PROCESS OPTIMIZATION OF TETRA ACETYL ETHYLENE DIAMINE ACTIVATED HYDROGEN PEROXIDE BLEACHING OF POPULUS NIGRA CTMP

    Qiang Zhao

    2010-02-01

    Full Text Available To enhance the bleaching efficiency, the activator of tetra acetyl ethylene diamine (TAED was used in conventional H2O2 bleaching. The H2O2/TAED bleaching system can accelerate the reaction rate and shorten bleaching time at relative low temperature, which can reduce the production cost. In this research, the process with hydrogen peroxide activated by TAED bleaching of Populus nigra chemi-thermo mechanical pulp was optimized. Suitable bleaching conditions were confirmed as follows: pulp consistency 10%, bleaching temperature 70oC, bleaching time 60 min when the charge of H2O2 was 4%, NaOH charge 2%, and molar ratio of TAED to H2O2 0.3. The pulp brightness gain reached 23.6% ISO with the optimized bleaching conditions. FTIR analysis indicated that the H2O2/TAED bleaching system can decrease carbonyl group further than that of conventional H2O2 bleaching, which contributed to the higher bleaching efficiency and final brightness. The H2O2/TAED bleaching had stronger oxidation ability on lignin than that of H2O2 bleaching.

  18. 3β-Acetyl Tormentic Acid (3ATA a Novel Modulator of ABCC Proteins Activity

    Cerli Rocha Gattass

    2012-06-01

    Full Text Available Multidrug resistance (MDR is considered the main cause of cancer chemotherapy failure and patient relapse. The active drug efflux mediated by transporter proteins of the ABC (ATP-binding cassette family is the most investigated mechanism leading to MDR. With the aim of inhibiting this transport and circumventing MDR, a great amount of work has been dedicated to identifying pharmacological inhibitors of specific ABC transporters. We recently showed that 3β-acetyl tormentic acid (3ATA had no effect on P-gp/ABCB1 activity. Herein, we show that 3ATA strongly inhibited the activity of MRP1/ABCC1. In the B16/F10 and Ma104 cell lines, this effect was either 20X higher or similar to that observed with MK571, respectively. Nevertheless, the low inhibitory effect of 3ATA on A549, a cell line that expresses MRP1-5, suggests that it may not inhibit other MRPs. The use of cells transfected with ABCC2, ABCC3 or ABCC4 showed that 3ATA was also able to modulate these transporters, though with an inhibition ratio lower than that observed for MRP1/ABCC1. These data point to 3ATA as a new ABCC inhibitor and call attention to its potential use as a tool to investigate the function of MRP/ABCC proteins or as a co-adjuvant in the treatment of MDR tumors.

  19. Improving polyketide and fatty acid synthesis by engineering of the yeast acetyl-CoA carboxylase.

    Choi, Jin Wook; Da Silva, Nancy A

    2014-10-10

    Polyketides and fatty acids are important in the production of pharmaceuticals, industrial chemicals, and biofuels. The synthesis of the malonyl-CoA building block, catalyzed by acetyl-CoA carboxylase (Acc1), is considered a limiting step to achieving high titers of polyketides and fatty acids in Saccharomyces cerevisiae. Acc1 is deactivated by AMP-activated serine/threonine protein kinase (Snf1) when glucose is depleted. To prevent this deactivation, the enzyme was aligned with the Rattus norvegicus (rat) Acc1 to identify a critical amino acid (Ser-1157) for phosphorylation and deactivation. Introduction of a S1157A mutation into Acc1 resulted in 9-fold higher specific activity following glucose depletion. The enzyme was tested in yeast engineered to produce the polyketide 6-methylsalisylic acid (6-MSA). Both 6-MSA and native fatty acid levels increased by 3-fold. Utilization of this modified Acc1 enzyme will also be beneficial for other products built from malonyl-CoA. PMID:25078432

  20. Microfluidic Mobility Shift Profiling of Lysine Acetyltransferases Enables Screening and Mechanistic Analysis of Cellular Acetylation Inhibitors.

    Sorum, Alexander W; Shrimp, Jonathan H; Roberts, Allison M; Montgomery, David C; Tiwari, Neil K; Lal-Nag, Madhu; Simeonov, Anton; Jadhav, Ajit; Meier, Jordan L

    2016-03-18

    Lysine acetyltransferases (KATs) are critical regulators of signaling in many diseases, including cancer. A major challenge in establishing the targetable functions of KATs in disease is a lack of well-characterized, cell-active KAT inhibitors. To confront this challenge, here we report a microfluidic mobility shift platform for the discovery and characterization of small molecule KAT inhibitors. Novel fluorescent peptide substrates were developed for four well-known KAT enzymes (p300, Crebbp, Morf, and Gcn5). Enzyme-catalyzed acetylation alters the electrophoretic mobility of these peptides in a microfluidic chip, allowing facile and direct monitoring of KAT activity. A pilot screen was used to demonstrate the utility of microfluidic mobility shift profiling to identify known and novel modulators of KAT activity. Real-time kinetic monitoring of KAT activity revealed that garcinol, a natural product KAT inhibitor used in cellular studies, exhibits time-dependent and detergent-sensitive inhibition, consistent with an aggregation-based mechanism. In contrast, the cell-permeable bisubstrate inhibitor Tat-CoA exhibited potent and time-independent KAT inhibition, highlighting its potential utility as a cellular inhibitor of KAT activity. These studies define microfluidic mobility shift profiling as a powerful platform for the discovery and characterization of small molecule inhibitors of KAT activity, and provide mechanistic insights potentially important for the application of KAT inhibitors in cellular contexts. PMID:26428393

  1. The effects of heating and chemical acetylation on ultrathin chitosan films

    Murray, Christopher A.

    We have prepared thin, uniform films by spincoating solutions of chitosan dissolved in dilute acetic acid onto silicon substrates while controlling the spin speed and the relative humidity inside the spincoater. Films with thicknesses between 20 and 600 nm (as measured using ellipsometry) and rms roughnesses of ˜1 nm measured by atomic force microscopy) were prepared. These films readily absorbed water in the presence of high humidity. We present the results of several experiments in which changes in the thickness, index of refraction and molecular environment in response to changes in relative humidity for ultrathin films of chitosan are examined as a function of exposure to temperatures above 150°C. Measurements performed using ellipsometry, surface plasmon resonance, and Fourier transform infrared absorption spectroscopy indicate that changes in the films caused by heating are similar to those associated with chemical acetylation, which is typically accomplished by exposure of chitosan to acetic anhydride. We present a possible mechanism by which chitosan is transformed by moderate heating into a material with increased chemical crosslinks and material properties that are similar to those of chitin. This heat-induced change may offer a simple method for stabilizing chitosan with respect to moisture and provide a non-toxic alternative to chemically converting chitosan into chitin.

  2. Differentially Expressed Genes in Hirudo medicinalis Ganglia after Acetyl-L-Carnitine Treatment

    Federighi, Giuseppe; Macchi, Monica; Bernardi, Rodolfo; Scuri, Rossana; Brunelli, Marcello; Durante, Mauro; Traina, Giovanna

    2013-01-01

    Acetyl-l-carnitine (ALC) is a naturally occurring substance that, when administered at supra-physiological concentration, is neuroprotective. It is involved in membrane stabilization and in enhancement of mitochondrial functions. It is a molecule of considerable interest for its clinical application in various neural disorders, including Alzheimer’s disease and painful neuropathies. ALC is known to improve the cognitive capability of aged animals chronically treated with the drug and, recently, it has been reported that it impairs forms of non-associative learning in the leech. In the present study the effects of ALC on gene expression have been analyzed in the leech Hirudo medicinalis. The suppression subtractive hybridisation methodology was used for the generation of subtracted cDNA libraries and the subsequent identification of differentially expressed transcripts in the leech nervous system after ALC treatment. The method detects differentially but also little expressed transcripts of genes whose sequence or identity is still unknown. We report that a single administration of ALC is able to modulate positively the expression of genes coding for functions that reveal a lasting effect of ALC on the invertebrate, and confirm the neuroprotective and neuromodulative role of the substance. In addition an important finding is the modulation of genes of vegetal origin. This might be considered an instance of ectosymbiotic mutualism. PMID:23308261

  3. The Role of Poly N Acetyl Glucosamine Nanofibers in Cutaneous Wound Healing

    Buff-Lindner, Amanda Haley

    Treatment of cutaneous wounds with poly-N-acetyl-glucosamine nanofibers (pGlcNAc), a novel polysaccharide material derived from a marine diatom, results in increases in wound closure, antibacterial activities and innate immune responses. Treatment with nanofibers results in increased defensin, small antimicrobial peptides, expression both in vitro and in vivo. Induction of defensin expression results in bacterial clearance in a cutaneous wound model. Our data show that Akt1 plays a central role in the regulation of these activities. Interestingly, pGlcNAc treatment of cutaneous wounds in mice results in decreased scar sizes. Additionally, treatment of cutaneous wounds with pGlcNAc results in increased elasticity and a rescue of tensile strength. Masson Trichrome staining suggests that pGlcNAc treated wounds exhibit decreased collagen content as well as increased collagen alignment with collagen fibers oriented similarly to unwounded tissue. Utilizing a fibrin gel assay to analyze the effect of pGlcNAc nanofiber treatment on fibroblast alignment in vitro, pGlcNAc stimulation of embedded fibroblasts results in fibroblasts alignment as compared to untreated controls, by a process that is Akt1 dependent. Our data show that in Akt1 null animals pGlcNAc treatment does not increase tensile strength or elasticity. Taken together, our findings suggest that pGlcNAc nanofibers stimulate an Akt1 dependent pathway that results in wound closure, the proper alignment of fibroblasts, decreased scarring, and increased tensile strength during cutaneous wound healing.

  4. Alcohol-induced histone acetylation reveals a gene network involved in alcohol tolerance.

    Alfredo Ghezzi

    Full Text Available Sustained or repeated exposure to sedating drugs, such as alcohol, triggers homeostatic adaptations in the brain that lead to the development of drug tolerance and dependence. These adaptations involve long-term changes in the transcription of drug-responsive genes as well as an epigenetic restructuring of chromosomal regions that is thought to signal and maintain the altered transcriptional state. Alcohol-induced epigenetic changes have been shown to be important in the long-term adaptation that leads to alcohol tolerance and dependence endophenotypes. A major constraint impeding progress is that alcohol produces a surfeit of changes in gene expression, most of which may not make any meaningful contribution to the ethanol response under study. Here we used a novel genomic epigenetic approach to find genes relevant for functional alcohol tolerance by exploiting the commonalities of two chemically distinct alcohols. In Drosophila melanogaster, ethanol and benzyl alcohol induce mutual cross-tolerance, indicating that they share a common mechanism for producing tolerance. We surveyed the genome-wide changes in histone acetylation that occur in response to these drugs. Each drug induces modifications in a large number of genes. The genes that respond similarly to either treatment, however, represent a subgroup enriched for genes important for the common tolerance response. Genes were functionally tested for behavioral tolerance to the sedative effects of ethanol and benzyl alcohol using mutant and inducible RNAi stocks. We identified a network of genes that are essential for the development of tolerance to sedation by alcohol.

  5. Nucleolin Acts as a Scavenger Receptor for Acetylated Low-Density Lipoprotein on Macrophages.

    Miki, Yuichi; Tachibana, Yoshihiro; Ohminato, Yukari; Fujiwara, Yasuyuki

    2015-01-01

    Although macrophage phagocytoses modified low-density lipoprotein (LDL), excessive accumulation of modified LDL induces macrophage foam cell formation, which is a feature of atherosclerotic plaque. Thus, the identification of scavenger receptor for modified LDL will provide better understanding of an atherosclerotic event. We recently showed that nucleolin expressed on macrophages acts as a scavenger receptor for various endogenous discarded products. Here, we investigated whether or not nucleolin is involved in the uptake of acetylated LDL (AcLDL). In contrast to normal LDL, AcLDL directly bound to immobilized nucleolin. AcLDL exhibited a higher affinity for macrophages than normal LDL. This binding of AcLDL was inhibited by anti-nucleolin antibody and antineoplastic guanine-rich oligonucleotide (AGRO), a nucleolin-specific oligonucleotide aptamer. In addition, AcLDL exhibited a higher affinity for HEK cells transfected with nucleolin than those without. Further, intracellular accumulation of AcLDL was also inhibited by anti-nucleolin antibody. The results of this study suggest that nucleolin expressed on macrophages is a receptor for AcLDL. PMID:26328500

  6. N -acetyl cysteine in clomiphene citrate resistant polycystic ovary syndrome: A review of reported outcomes

    Lekha Saha

    2013-01-01

    Full Text Available Clomiphene citrate (CC has been the gold-standard drug for ovulation induction in polycystic ovary syndrome (PCOS, but still CC resistance is seen in approximately 15-40% in women with PCOS. N-acetyl cysteine (NAC, a safe and cheap drug available in the market many years ago as mucolytic agent, was found to have a role in infertility management. Recently, some reports discussed the possible beneficial effects of NAC on ovulation. The biological properties of the NAC make this drug a potential candidate for its use in the infertility treatment, especially in the PCOS in inducing or augmenting ovulation. An updated electronic search was performed through PUBMED, MEDLINE, and COCHRANE and focused on peer-reviewed, full text, randomized controlled trials, and observational cohort or case-control studies for role of NAC in CC-resistant PCOS. Thorough search through all the clinical studies showed mixed results. Studies with positive results showed improvement in induction of ovulation as compared to negative studies showing contrary results. More randomized clinical trials are still needed to establish its definitive role in CC-resistant PCOS.

  7. Monocyte polarization: the relationship of genome-wide changes in H4 acetylation with polarization.

    Zhang, Z; Song, L; Maurer, K; Bagashev, A; Sullivan, K E

    2011-09-01

    The character of monocytes is both molded by and contributes to ongoing immune responses. We hypothesized that monocyte polarization could have durable qualities and these would be mediated partly by changes in the chromatin. We defined genome-wide expression and histone H4 acetylation (H4ac) changes after γ-interferon (IFN), α-IFN and interleukin-4 treatment. To identify genes with altered potential for expression, we stimulated polarized monocytes and identified genes up- or downregulated after polarization and stimulation but not either treatment alone. We also defined durability after an 18-h or 3-day washout. Genes uniquely regulated after the combination of polarization and stimulus were durably altered, with 51% of the effects being durable. This gene set was highly enriched for cytokine-induced alterations in H4ac, with P-values ranging from 10(-24) to 10(-37). Certain regulons defined by patterns of expression were also associated with altered H4ac, with P-values ranging from 10(-4) to 10(-29). Networking software revealed a high density of mitogen-activated protein (MAP) kinase nodes in these clusters. Therefore, some changes in monocyte gene expression were sustained over a 3-day period. These durably altered gene sets were enriched for changes in H4ac and were associated with potential MAP kinase effects. PMID:21451557

  8. Aberrant histone acetylation contributes to elevated interleukin-6 production in rheumatoid arthritis synovial fibroblasts.

    Wada, Takuma Tsuzuki; Araki, Yasuto; Sato, Kojiro; Aizaki, Yoshimi; Yokota, Kazuhiro; Kim, Yoon Taek; Oda, Hiromi; Kurokawa, Riki; Mimura, Toshihide

    2014-02-21

    Accumulating evidence indicates that epigenetic aberrations have a role in the pathogenesis of rheumatoid arthritis (RA). However, reports on histone modifications are as yet quite limited in RA. Interleukin (IL)-6 is an inflammatory cytokine which is known to be involved in the pathogenesis of RA. Here we report the role of histone modifications in elevated IL-6 production in RA synovial fibroblasts (SFs). The level of histone H3 acetylation (H3ac) in the IL-6 promoter was significantly higher in RASFs than osteoarthritis (OA) SFs. This suggests that chromatin structure is in an open or loose state in the IL-6 promoter in RASFs. Furthermore, curcumin, a histone acetyltransferase (HAT) inhibitor, significantly reduced the level of H3ac in the IL-6 promoter, as well as IL-6 mRNA expression and IL-6 protein secretion by RASFs. Taken together, it is suggested that hyperacetylation of histone H3 in the IL-6 promoter induces the increase in IL-6 production by RASFs and thereby participates in the pathogenesis of RA. PMID:24513290

  9. Isomerizational and conformational study of 3-fluorophenylamino-2-acetyl propenenitrile (FPAAPN)

    Gatial, A.; Dorotíková, S.; Plevová, K.; Milata, V.; Prónayová, N.; Matějka, P.

    2015-06-01

    The isomers and conformers of push-pull 3-fluorophenylamino-2-acetyl propenenitrile (FH4C6)sbnd NHsbnd CHdbnd C(CN)(COCH3) (FPAAPN) have been studied experimentally by NMR and vibrational spectroscopy and theoretically by ab initio calculations at MP2 and DFT B3LYP levels in various basis sets. The IR and Raman spectra of FPAAPN as a solid and as a solute in various solvents have been recorded. The NMR spectra were obtained in chloroform, acetone, acetonitrile and dimethylsulfoxide at room temperature. FPAAPN was prepared as a pure Z-isomer with an intramolecular hydrogen bond. According to the NMR spectra in chloroform the studied compound exists as a single ZZa entity. On the other hand, in more polar solvents the isomerization process occured and an additional EZa confomer was detected. The influence of the environment polarity on this conformational equilibrium is discussed with respect to the SCRF solvent effect calculations using IEFPCM model. The observed IR and Raman bands were compared with calculated MP2/6-311G∗∗ harmonic vibrational frequencies and assigned on the basis of potential energy distribution.

  10. 1,3,4-Tri-O-acetyl-2-N-(trifluoroacetyl-β-l-fucose

    David C. McCutcheon

    2014-02-01

    Full Text Available The title compound, C14H18F3NO8, was produced through conjugation of 1,3,4-tri-O-acetyl-2-azidodeoxy-α,β-l-fucose with trifluoroacetyl chloride in the presence of bis(diphenylphosphinoethane in tetrahydrofuran at room temperature. The X-ray crystal structure reveals that the β-anomer of the product mixture crystallizes from ethyl acetate/hexanes. The compound exists in a typical chair conformation with the maximum possible number of substituents, four out of five, located in the sterically preferred equatorial positions. The major directional force facilitating packing of the molecules are N—H...O hydrogen bonds involving the amide moieties of neighboring molecules, which connect molecules stacked along the a-axis direction into infinite strands with a C11(4 graph-set motif. Formation of the strands is assisted by a number of weaker C—H...O interactions involving the methine and methyl H atoms. These strands are connected through further C—H...O and C—H...F interactions into a three dimensional network

  11. Hepatoprotective and antioxidant activity of N-acetyl cysteine in carbamazepine-administered rats

    Eswaran Maheswari

    2014-01-01

    Full Text Available Objectives: The present study evaluates the hepatoprotective activity of N-acetyl cysteine (NAC against carbamazepine (CBZ-induced hepatotoxicity. Materials and Methods: Rats were treated with CBZ (50 mg/kg p.o. and CBZ supplemented with NAC 50, 100 and 200 mg/kg for 45 days, after which blood samples were collected and subjected to liver function tests. Animals were killed, liver was separated, weighed and the levels of antioxidants and liver enzymes were estimated. In addition, histopathological investigation was also performed. Results: Serum glutamate pyruvate transaminase (SGPT, serum glutamate oxaloacetate (SGOT transaminase, alkaline phosphatase (ALP, bilirubin, lipid peroxidation, absolute and relative liver weights were significantly (P < 0.05 elevated, whereas serum levels of albumin, total protein and body weight were decreased in the CBZ-treated animals. CBZ also produced vacuolar degeneration, centrilobular congestion and hepatic necrosis as evidenced from histopathological report. NAC significantly reduced the levels of serum transaminase, ALP, bilirubin and liver weight and increased the levels of total protein, albumin and body weight. Conclusion: It was observed that NAC increased the glutathione (GSH content, reduced lipid peroxidation and reversed the CBZ-induced histopathological abnormalities. CBZ-induced hepatotoxicity may be due its toxic epoxide metabolite-induced oxidative stress.

  12. N-acetyl -β-D-glucosaminidase activity in cow milk as an indicator of mastitis.

    Hovinen, Mari; Simojoki, Heli; Pösö, Reeta; Suolaniemi, Jenni; Kalmus, Piret; Suojala, Leena; Pyörälä, Satu

    2016-05-01

    Activity of lysosomal N-acetyl-β-d-glucosaminidase (NAGase) in milk has been used as an indicator of bovine mastitis. We studied NAGase activity of 808 milk samples from healthy quarters and quarters of cows with spontaneous subclinical and clinical mastitis. Associations between milk NAGase activity and milk somatic cell count (SCC), mastitis causing pathogen, quarter, parity, days in milk (DIM) and season were studied. In addition, the performance of NAGase activity in detecting clinical and subclinical mastitis and distinguishing infections caused by minor and major bacteria was investigated. Our results indicate that NAGase activity can be used to detect both subclinical and clinical mastitis with a high level of accuracy (0·85 and 0·99). Incomplete correlation between NAGase activity and SCC suggests that a substantial proportion of NAGase activity comes from damaged epithelial cells of the udder in addition to somatic cells. We therefore recommend determination of NAGase activity from quarter foremilk after at least six hours from the last milking using the method described. Samples should be frozen before analysis. NAGase activity should be interpreted according to DIM, at least during the first month of lactation. Based on the results of the present study, a reference value for normal milk NAGase activity of 0·1-1·04 pmoles 4-MU/min/μl for cows with ≥30 DIM (196 samples) could be proposed. We consider milk NAGase activity to be an accurate indicator of subclinical and clinical mastitis. PMID:27210494

  13. Anti-bis(monoacylglycero)phosphate antibody accumulates acetylated LDL-derived cholesterol in cultured macrophages.

    Delton-Vandenbroucke, Isabelle; Bouvier, Jerome; Makino, Asami; Besson, Nelly; Pageaux, Jean-François; Lagarde, Michel; Kobayashi, Toshihide

    2007-03-01

    Bis(monoacylglycero)phosphate (BMP), also called lysobisphosphatidic acid, is a phospholipid highly enriched in the internal membranes of multivesicular late endosomes, in which it forms specialized lipid domains. It has been suggested that BMP-rich membranes regulate cholesterol transport. Here, we examine the effects of an anti-BMP antibody on cholesterol metabolism and transport in two macrophage cell lines, RAW 264.7 and THP-1, during loading with acetylated low density lipoprotein (AcLDL). Anti-BMP antibody was internalized and accumulated in both macrophage cell types. Cholesterol staining with filipin and mass measurements indicate that AcLDL-stimulated accumulation of free cholesterol (FC) was enhanced in macrophages that had accumulated the antibody. Unlike the hydrophobic amine U18666A (3-beta-[2-(diethylamino)ethoxy]androst-5-en-17-one), esterification of AcLDL-derived cholesterol by ACAT was not modified after anti-BMP treatment. AcLDL loading led to an increase of FC in the plasma membrane. This increase was further enhanced in anti-BMP-treated macrophages. However, cholesterol efflux to HDL was reduced in antibody-treated cells. These results suggest that the accumulation of anti-BMP antibody alters cholesterol homeostasis in AcLDL-loaded macrophages. PMID:17146116

  14. N-acetyl-cysteine attenuates neuropathic pain by suppressing matrix metalloproteinases.

    Li, Jiajie; Xu, Lujie; Deng, Xueting; Jiang, Chunyi; Pan, Cailong; Chen, Lu; Han, Yuan; Dai, Wenling; Hu, Liang; Zhang, Guangqin; Cheng, Zhixiang; Liu, Wentao

    2016-08-01

    The treatment of neuropathic pain remains a clinical challenge because of its unclear mechanisms and broad clinical morbidity. Matrix metalloproteinase (MMP)-9 and MMP-2 have previously been described as key components in neuropathic pain because of their facilitation of inflammatory cytokine maturation and induction of neural inflammation. Therefore, the inhibition of MMPs may represent a novel therapeutic approach to the treatment of neuropathic pain. In this study, we report that N-acetyl-cysteine (NAC), which is a broadly used respiratory drug, significantly attenuates neuropathic pain through a unique mechanism of MMP inhibition. Both the in vitro (0.1 mM) and in vivo application of NAC significantly suppressed the activity of MMP-9/2. Orally administered NAC (50, 100, and 200 mg/kg) not only postponed the occurrence but also inhibited the maintenance of chronic constrictive injury (CCI)-induced neuropathic pain in rats. The administration of NAC blocked the maturation of interleukin-1β, which is a critical substrate of MMPs, and markedly suppressed the neuronal activation induced by CCI, including inhibiting the phosphorylation of protein kinase Cγ, NMDAR1, and mitogen-activated protein kinases. Finally, NAC significantly inhibited CCI-induced microglia activation but elicited no notable effects on astrocytes. These results demonstrate an effective and safe approach that has been used clinically to alleviate neuropathic pain through the powerful inhibition of the activation of MMPs. PMID:27075430

  15. Variation in NAT2 acetylation phenotypes is associated with differences in food-producing subsistence modes and ecoregions in Africa

    Podgorná, Eliška; Diallo, I.; Vangenot, Ch.; Sanchez-Mazas, A.; Sabbagh, A.; Černý, Viktor; Poloni, E. S.

    2015-01-01

    Roč. 15, č. 263 (2015). ISSN 1471-2148 R&D Projects: GA ČR GA13-37998S Institutional support: RVO:67985912 Keywords : NAT2 * acetylation polymorphism * African Sahel * pastoral nomads * subsistence mode * ecoregion * natural selection Subject RIV: AC - Archeology, Anthropology, Ethnology Impact factor: 3.368, year: 2014 http://www.biomedcentral.com/1471-2148/15/263

  16. CHBPR N-Acetyl-Seryl-Aspartyl-Lysyl-Proline Attenuates Renal Injury and Dysfunction in Hypertensive Rats with Reduced Renal Mass

    LIAO, Tang-dong; Yang, Xiao-Ping; D’Ambrosio, Martin; Zhang, Yanlu; Rhaleb, Nour-Eddine; Carretero, Oscar A.

    2009-01-01

    N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) is a naturally occurring peptide whose plasma concentration is increased 4- to 5-fold by angiotensin-converting enzyme inhibitors. We previously reported that in models of both hypertension and postmyocardial infarction, Ac-SDKP reduces cardiac inflammation and fibrosis. However, it is unknown whether Ac-SDKP can prevent or reverse renal injury and dysfunction in hypertension. In the present study, we tested the hypothesis that in rats with 5/6 ...

  17. Mimicking Insect Communication: Release and Detection of Pheromone, Biosynthesized by an Alcohol Acetyl Transferase Immobilized in a Microreactor

    Lourdes Muñoz; Nikolay Dimov; Gerard Carot-Sans; Bula, Wojciech P.; Angel Guerrero; Gardeniers, Han J. G. E.

    2012-01-01

    Infochemical production, release and detection of (Z,E)-9,11-tetradecadienyl acetate, the major component of the pheromone of the moth Spodoptera littoralis is achieved in a novel microfluidic system, designed to mimic the final step of the pheromone biosynthesis by immobilized recombinant alcohol acetyl transferase. The microfluidic system is part of an "artificial gland", i.e. a chemoemitter that comprises a microreactor connected to a microevaporator and is able to produce a...

  18. Interleukin 2 gene transcription is regulated by Ikaros-induced changes in histone acetylation in anergic T cells

    Bandyopadhyay, Sanmay; Duré, Myrianne; Paroder, Monika; Soto-Nieves, Noemí; Puga, Irene; Macián, Fernando

    2007-01-01

    In T cells anergy may be evoked by an unbalanced stimulation of the T-cell receptor in the absence of costimulation. Anergic T cells are unresponsive to new antigen receptor engagement and do not produce interleukin 2. We present evidence that anergizing stimuli induce changes in histone acetylation, which mediates transcriptional repression of interleukin 2 expression. In response to calcium signaling, anergic T cells up-regulate the expression of Ikaros, a zinc finger transcription factor e...

  19. Production of N-acetyl-D-neuraminic acid using two sequential enzymes overexpressed as double-tagged fusion proteins

    Cheng Chung-Hsien

    2009-07-01

    Full Text Available Abstract Background Two sequential enzymes in the production of sialic acids, N-acetyl-D-glucosamine 2-epimerase (GlcNAc 2-epimerase and N-acetyl-D-neuraminic acid aldolase (Neu5Ac aldolase, were overexpressed as double-tagged gene fusions. Both were tagged with glutathione S-transferase (GST at the N-terminus, but at the C-terminus, one was tagged with five contiguous aspartate residues (5D, and the other with five contiguous arginine residues (5R. Results Both fusion proteins were overexpressed in Escherichia coli and retained enzymatic activity. The fusions were designed so their surfaces were charged under enzyme reaction conditions, which allowed isolation and immobilization in a single step, through a simple capture with either an anionic or a cationic exchanger (Sepharose Q or Sepharose SP that electrostatically bound the 5D or 5R tag. The introduction of double tags only marginally altered the affinity of the enzymes for their substrates, and the double-tagged proteins were enzymatically active in both soluble and immobilized forms. Combined use of the fusion proteins led to the production of N-acetyl-D-neuraminic acid (Neu5Ac from N-acetyl-D-glucosamine (GlcNAc. Conclusion Double-tagged gene fusions were overexpressed to yield two enzymes that perform sequential steps in sialic acid synthesis. The proteins were easily immobilized via ionic tags onto ionic exchange resins and could thus be purified by direct capture from crude protein extracts. The immobilized, double-tagged proteins were effective for one-pot enzymatic production of sialic acid.

  20. Role of histone acetylation in long-term neurobehavioral effects of neonatal Exposure to sevoflurane in rats.

    Jia, Min; Liu, Wen-Xue; Yang, Jiao-Jiao; Xu, Ning; Xie, Ze-Min; Ju, Ling-Sha; Ji, Mu-Huo; Martynyuk, Anatoly E; Yang, Jian-Jun

    2016-07-01

    Human studies, and especially laboratory studies, provide evidence that early life exposure to general anesthesia may affect neurocognitive development via largely unknown mechanisms. We explored whether hippocampal histone acetylation had a role in neurodevelopmental effects of sevoflurane administered to neonatal rats. Male Sprague-Dawley rats were exposed to 3% sevoflurane or were subjected to maternal separation only for 2h daily at postnatal days 6, 7, and 8. The histone deacetylase inhibitor, sodium butyrate (250mg/kg, intraperitoneally), or saline was administered starting 2h prior to anesthesia or maternal separation and continued daily until the end of behavioral tests, which were performed between postnatal days 33 and 50. Upon completion of the behavioral tests, the brain tissues were harvested for further analysis. Rats neonatally exposed to sevoflurane exhibited decreased freezing time in the fear conditioning contextual test and increased escape latency, decreased time in target quadrant, and number of platform crossings in the Morris water maze test. The sevoflurane-exposed rats had lower hippocampal density of dendritic spines, reduced levels of the brain-derived neurotrophic factor, c-fos protein, microtubule-associated protein 2, synapsin1, postsynaptic density protein 95, pCREB/CREB, CREB binding protein, and acetylated histones H3 and H4, and increased levels of histone deacetylases 3 and 8. These neurobehavioral abnormalities were normalized in the sevoflurane-exposed rats treated with sodium butyrate. Our findings provide evidence that neonatal exposure to sevoflurane induces neurobehavioral abnormalities and long-lasting alterations in histone acetylation; normalization of histone acetylation may alleviate the neurodevelopmental side effects of the anesthetic. PMID:27001149